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< 1 2 3 4 >Solved |
Name |
Tags |
Solutions |
Index |
Contest |
Type |
Points |
Tutorial |
Rating Level |
|---|---|---|---|---|---|---|---|---|---|
| 9378 | k-rounding | brute force math number theory | Statement | A | Технокубок 2018 - Отборочный Раунд 1 {858} | PROGRAMMING | Codeforces Round 434 Div.1+Div.2 (and Technocup 2018 — Elimination Round 1) Editorial | 1200 | |
| 27116 | Mahmoud and Ehab and the bipartiteness | dfs and similar graphs trees | Statement | B | Codeforces Round 435 (Div. 2) {862} | PROGRAMMING | Codeforces round #435 editorial | 1400 | |
| 9833 | Maximum splitting | dp greedy math number theory | Statement | C | Technocup 2018 - Elimination Round 2 {870} | PROGRAMMING | Editorial Codeforces Round 440 Div.1+Div.2 (and Technocup 2018 — Elimination Round 2) | 1300 | |
| 728 | Paths | data structures number theory | Statement | F | Technocup 2018 - Elimination Round 2 {870} | PROGRAMMING | Editorial Codeforces Round 440 Div.1+Div.2 (and Technocup 2018 — Elimination Round 2) | 2600 | |
| 10444 | Divisiblity of Differences | implementation math number theory | Statement | B | Codeforces Round 441 (Div. 2, by Moscow Team Olympiad) {876} | PROGRAMMING | Codeforces Round #441. Editorial. | 1300 | |
| 14958 | Pride | brute force dp greedy math number theory | Statement | A | Codeforces Round 446 (Div. 1) {891} | PROGRAMMING | Codeforces Round #446 Editorial | 1600 | |
| 4307 | Counting Arrays | combinatorics dp math number theory | Statement | E | Educational Codeforces Round 33 (Rated for Div. 2) {893} | PROGRAMMING | 55989 | 2000 | |
| 4720 | Ralph And His Magic Field | combinatorics constructive algorithms math number theory | Statement | B | Codeforces Round 447 (Div. 2) {894} | PROGRAMMING | Codeforces Round #447 (Div.2 Only) Editorial | 1800 | |
| 705 | Nephren Runs a Cinema | chinese remainder theorem combinatorics math number theory | Statement | D | Codeforces Round 449 (Div. 1) {896} | PROGRAMMING | Codeforces Round #449 Editorial | 2800 | |
| 10782 | Proper Nutrition | brute force implementation number theory | Statement | B | Codeforces Round 451 (Div. 2) {898} | PROGRAMMING | Codeforces Round #451 (Div.2) Editorial | 1300 | |
| 8441 | Position in Fraction | math number theory | Statement | B | Codeforces Round 450 (Div. 2) {900} | PROGRAMMING | Codeforces Round #450(Div. 2). Editorial. | 1300 | |
| 3885 | Unusual Sequences | bitmasks combinatorics dp math number theory | Statement | D | Codeforces Round 450 (Div. 2) {900} | PROGRAMMING | Codeforces Round #450(Div. 2). Editorial. | 2100 | |
| 12065 | Coloring a Tree | dfs and similar dsu greedy | Statement | B | Codeforces Round 453 (Div. 2) {902} | PROGRAMMING | Codeforces Round #453 (Div. 1 & Div. 2) Editorial | 1300 | |
| 2801 | Power Tower | chinese remainder theorem math number theory | Statement | D | Codeforces Round 454 (Div. 1, based on Technocup 2018 Elimination Round 4) {906} | PROGRAMMING | Editorial Codeforces Round 454 (and Technocup 2018 — Elimination Round 4) | 2600 | |
| 14185 | New Year's Eve | bitmasks constructive algorithms number theory | Statement | B | Codeforces Round 456 (Div. 2) {912} | PROGRAMMING | Codeforces Round #456 (Div. 2) Editorial | 1400 | |
| 2125 | Prime Gift | binary search dfs and similar math meet-in-the-middle number theory two pointers | Statement | E | Codeforces Round 456 (Div. 2) {912} | PROGRAMMING | Codeforces Round #456 (Div. 2) Editorial | 2600 | |
| 5159 | Too Easy Problems | binary search brute force data structures greedy sortings | Statement | D | Hello 2018 {913} | PROGRAMMING | Tutorial | 1800 | |
| 267 | Power Substring | math number theory | Statement | G | Hello 2018 {913} | PROGRAMMING | Tutorial | 3100 | |
| 6555 | Bash and a Tough Math Puzzle | data structures number theory | Statement | D | Codecraft-18 and Codeforces Round 458 (Div. 1 + Div. 2, combined) {914} | PROGRAMMING | Tutorial | 1900 | |
| 1516 | Coprime Arrays | math number theory | Statement | G | Educational Codeforces Round 36 (Rated for Div. 2) {915} | PROGRAMMING | 57123 | 2500 | |
| 31984 | Perfect Number | binary search brute force dp implementation number theory | Statement | B | Codeforces Round 460 (Div. 2) {919} | PROGRAMMING | Codeforces Round #460 (Div. 2) Editorial | 1100 | |
| 2528 | Congruence Equation | chinese remainder theorem math number theory | Statement | E | Codeforces Round 460 (Div. 2) {919} | PROGRAMMING | Codeforces Round #460 (Div. 2) Editorial | 2100 | |
| 9011 | SUM and REPLACE | brute force data structures dsu number theory | Statement | F | Educational Codeforces Round 37 (Rated for Div. 2) {920} | PROGRAMMING | T | 2000 | |
| 2057 | List Of Integers | binary search bitmasks brute force combinatorics math number theory | Statement | G | Educational Codeforces Round 37 (Rated for Div. 2) {920} | PROGRAMMING | T | 2300 | |
| 7743 | Cave Painting | brute force number theory | Statement | C | Codeforces Round 461 (Div. 2) {922} | PROGRAMMING | 57605 | 1600 | |
| 768 | Divisibility | constructive algorithms dp greedy number theory | Statement | F | Codeforces Round 461 (Div. 2) {922} | PROGRAMMING | 57605 | 2500 | |
| 5463 | Primal Sport | math number theory | Statement | A | VK Cup 2018 - Round 1 {923} | PROGRAMMING | VK Cup 2018 Round 1 and CF Round #470 (div. 1 & 2) editorial | 1700 | |
| 7307 | Vile Grasshoppers | brute force math number theory | Statement | B | Codeforces Round 467 (Div. 2) {937} | PROGRAMMING | Codeforces Round #467, Editorial | 1500 | |
| 11513 | Weird Subtraction Process | math number theory | Statement | B | Educational Codeforces Round 39 (Rated for Div. 2) {946} | PROGRAMMING | 58210 | 1200 | |
| 2932 | Sad powers | binary search math number theory | Statement | C | Codeforces Round 471 (Div. 2) {955} | PROGRAMMING | Editorial | 2100 | |
| 3286 | Mahmoud and Ehab and another array construction task | constructive algorithms greedy math number theory | Statement | D | Codeforces Round 473 (Div. 2) {959} | PROGRAMMING | Codeforces round #473 editorial | 2000 | |
| 1799 | Partitions | combinatorics math number theory | Statement | G | Educational Codeforces Round 41 (Rated for Div. 2) {961} | PROGRAMMING | Educational Codeforces Round 41 Editorial | 2700 | |
| 3666 | Alternating Sum | math number theory | Statement | A | Tinkoff Internship Warmup Round 2018 and Codeforces Round 475 (Div. 1) {963} | PROGRAMMING | Editorial Tinkoff Internship Warmup Round 2018 and Codeforces Round #475 (Div. 1 + Div. 2) | 1800 | |
| 702 | Cutting Rectangle | brute force math number theory | Statement | C | Tinkoff Internship Warmup Round 2018 and Codeforces Round 475 (Div. 1) {963} | PROGRAMMING | Editorial Tinkoff Internship Warmup Round 2018 and Codeforces Round #475 (Div. 1 + Div. 2) | 2600 | |
| 26548 | Cyclic Components | dfs and similar dsu graphs | Statement | E | Codeforces Round 479 (Div. 3) {977} | PROGRAMMING | Codeforces Round #479 (Div. 3) Editorial | 1500 | |
| 2254 | Kuro and GCD and XOR and SUM | binary search bitmasks brute force data structures dp dsu greedy math number theory strings trees | Statement | D | Codeforces Round 482 (Div. 2) {979} | PROGRAMMING | 1750.0 | Codeforces Round #482 (Div. 2) Editorial | 2200 |
| 3089 | Perfect Groups | dp math number theory | Statement | D | Codeforces Round 480 (Div. 2) {980} | PROGRAMMING | Tutorial | 2100 | |
| 875 | Billiard | geometry number theory | Statement | E | Codeforces Round 484 (Div. 2) {982} | PROGRAMMING | Editorial | 2500 | |
| 8576 | Fair | graphs greedy number theory shortest paths | Statement | A | Codeforces Round 485 (Div. 1) {986} | PROGRAMMING | Codeforces Round #485 Editorial | 1600 | |
| 957 | Prince's Problem | brute force data structures math number theory trees | Statement | E | Codeforces Round 485 (Div. 1) {986} | PROGRAMMING | Codeforces Round #485 Editorial | 2900 | |
| 854 | Oppa Funcan Style Remastered | graphs math number theory shortest paths | Statement | F | Codeforces Round 485 (Div. 1) {986} | PROGRAMMING | Codeforces Round #485 Editorial | 3200 | |
| 2422 | GCD Counting | divide and conquer dp dsu number theory trees | Statement | G | Educational Codeforces Round 45 (Rated for Div. 2) {990} | PROGRAMMING | Educational Codeforces Round 45 Editorial | 2400 | |
| 6811 | Nastya Studies Informatics | math number theory | Statement | B | Codeforces Round 489 (Div. 2) {992} | PROGRAMMING | 60083 | 1700 | |
| 976 | Number Clicker | divide and conquer graphs meet-in-the-middle number theory | Statement | E | Codeforces Round 492 (Div. 1) [Thanks, uDebug!] {995} | PROGRAMMING | Editorial for Codeforces Round #492 [Thanks u-Debug!] | 2700 | |
| 11580 | Polycarp and Div 3 | dp greedy number theory | Statement | D | Codeforces Round 496 (Div. 3) {1005} | PROGRAMMING | Codeforces Round 496 (Div. 3): Problem Tutorials | 1500 | |
| 1062 | Pave the Parallelepiped | bitmasks brute force combinatorics math number theory | Statement | B | Codeforces Round 497 (Div. 1) {1007} | PROGRAMMING | Editorial for Codeforces Round #497 by Skyglow | 2400 | |
| 6059 | Border | number theory | Statement | C | Codeforces Round 499 (Div. 1) {1010} | PROGRAMMING | 60851 | 1800 | |
| 364 | Appropriate Team | bitmasks math number theory | Statement | G | Educational Codeforces Round 48 (Rated for Div. 2) {1016} | PROGRAMMING | Разбор Educational Codeforces Round 48 | 2800 | |
| 8588 | Weakened Common Divisor | brute force greedy number theory | Statement | B | Codeforces Round 505 (rated, Div. 1 + Div. 2, based on VK Cup 2018 Final) {1025} | PROGRAMMING | Codeforces Round #505 Editorial | 1600 | |
| 4290 | Recovering BST | brute force dp math number theory trees | Statement | D | Codeforces Round 505 (rated, Div. 1 + Div. 2, based on VK Cup 2018 Final) {1025} | PROGRAMMING | Codeforces Round #505 Editorial | 2000 | |
| 386 | X-mouse in the Campus | bitmasks math number theory | Statement | G | Educational Codeforces Round 49 (Rated for Div. 2) {1027} | PROGRAMMING | Educational Codeforces Round 49 Editorial | 2800 | |
| 2864 | Multicolored Markers | binary search brute force math number theory | Statement | F | Codeforces Round 506 (Div. 3) {1029} | PROGRAMMING | Codeforces Round #506 (Div. 3) Editorial | 2100 | |
| 6292 | Vasya and Triangle | geometry number theory | Statement | D | Technocup 2019 - Elimination Round 1 {1030} | PROGRAMMING | Сodeforces Round 512 (and Technocup — Elimination Round 1) Editorial | 1700 | |
| 441 | Linear Congruential Generator | number theory | Statement | G | Technocup 2019 - Elimination Round 1 {1030} | PROGRAMMING | Сodeforces Round 512 (and Technocup — Elimination Round 1) Editorial | 3000 | |
| 12252 | Square Difference | math number theory | Statement | B | Lyft Level 5 Challenge 2018 - Elimination Round {1033} | PROGRAMMING | The Lyft Level 5 Challenge 2018 Elimination Round (Div. 1 + Div. 2) Editorial | 1100 | |
| 2649 | Divisors | interactive math number theory | Statement | D | Lyft Level 5 Challenge 2018 - Elimination Round {1033} | PROGRAMMING | The Lyft Level 5 Challenge 2018 Elimination Round (Div. 1 + Div. 2) Editorial | 2000 | |
| 10139 | Enlarge GCD | number theory | Statement | A | Codeforces Round 511 (Div. 1) {1034} | PROGRAMMING | Codeforces Round #511 Editorial | 1700 | |
| 1141 | Region Separation | combinatorics dp number theory trees | Statement | C | Codeforces Round 511 (Div. 1) {1034} | PROGRAMMING | Codeforces Round #511 Editorial | 2900 | |
| 1796 | Covered Points | fft geometry number theory | Statement | E | Educational Codeforces Round 50 (Rated for Div. 2) {1036} | PROGRAMMING | 61727 | 2300 | |
| 1895 | Relatively Prime Powers | combinatorics math number theory | Statement | F | Educational Codeforces Round 50 (Rated for Div. 2) {1036} | PROGRAMMING | 61727 | 2400 | |
| 3133 | Make It One | bitmasks combinatorics dp math number theory shortest paths | Statement | F | Codeforces Round 519 by Botan Investments {1043} | PROGRAMMING | Codeforces Round #519 Editorial | 2500 | |
| 625 | Space Isaac | hashing number theory | Statement | B | Bubble Cup 11 - Finals [Online Mirror, Div. 1] {1045} | PROGRAMMING | E | 2500 | |
| 19035 | Relatively Prime Pairs | greedy math number theory | Statement | B | Educational Codeforces Round 51 (Rated for Div. 2) {1051} | PROGRAMMING | Educational Codeforces Round 51 Editorial | 1000 | |
| 318 | Epic Convolution | chinese remainder theorem fft math number theory | Statement | H | Mail.Ru Cup 2018 Round 1 {1054} | PROGRAMMING | Editorial | 3400 | |
| 2061 | Lucky Days | math number theory | Statement | C | Mail.Ru Cup 2018 Round 2 {1055} | PROGRAMMING | Mail.Ru Cup 2018 Round 2 — analysis | 1900 | |
| 4568 | Divide Candies | math number theory | Statement | B | Mail.Ru Cup 2018 Round 3 {1056} | PROGRAMMING | Mail.Ru Cup 2018 Round 3 Editorial | 1600 | |
| 10992 | Multiplicity | data structures dp implementation math number theory | Statement | C | Codeforces Round 523 (Div. 2) {1061} | PROGRAMMING | Tutorial (en) | 1700 | |
| 10040 | Math | greedy math number theory | Statement | B | Codeforces Round 520 (Div. 2) {1062} | PROGRAMMING | Tutorial | 1600 | |
| 13277 | LCM | math number theory | Statement | B | Codeforces Round 518 (Div. 2) [Thanks, Mail.Ru!] {1068} | PROGRAMMING | E | 1200 | |
| 2669 | Find a Number | dp graphs number theory shortest paths | Statement | A | 2018-2019 ICPC, NEERC, Southern Subregional Contest (Online Mirror, ACM-ICPC Rules, Teams Preferred) {1070} | PROGRAMMING | Solution to problem M. Algoland and Berland of 2018-2019 ICPC, NEERC | 2200 | |
| 14809 | Divisor Subtraction | implementation math number theory | Statement | B | Educational Codeforces Round 54 (Rated for Div. 2) {1076} | PROGRAMMING | E | 1200 | |
| 2841 | Missing Numbers | binary search constructive algorithms greedy math number theory | Statement | E | Avito Cool Challenge 2018 {1081} | PROGRAMMING | 63888 | 1900 | |
| 10617 | New Year and the Sphere Transmission | math number theory | Statement | C | Good Bye 2018 {1091} | PROGRAMMING | Editorial | 1400 | |
| 242 | New Year and the Factorisation Collaboration | interactive math number theory | Statement | G | Good Bye 2018 {1091} | PROGRAMMING | Editorial | 3100 | |
| 3244 | Makoto and a Blackboard | dp math number theory probabilities | Statement | D | Hello 2019 {1097} | PROGRAMMING | 64310 | 2200 | |
| 1531 | Alex and a TV Show | bitmasks combinatorics number theory | Statement | F | Hello 2019 {1097} | PROGRAMMING | 64310 | 2400 | |
| 372 | Fedya the Potter | binary search implementation math number theory | Statement | E | Codeforces Round 530 (Div. 1) {1098} | PROGRAMMING | 64331 | 3400 | |
| 5548 | GCD Counting | data structures dfs and similar dp number theory trees | Statement | D | Educational Codeforces Round 58 (Rated for Div. 2) {1101} | PROGRAMMING | 64483 | 2000 | |
| 386 | Radix sum | fft math number theory | Statement | E | Codeforces Round 534 (Div. 1) {1103} | PROGRAMMING | Codeforces Round #534 — Editorial | 3300 | |
| 1232 | Lunar New Year and a Recursive Sequence | math matrices number theory | Statement | F | Codeforces Round 536 (Div. 2) {1106} | PROGRAMMING | Tutorial | 2400 | |
| 17931 | Digital root | math number theory | Statement | B | Educational Codeforces Round 59 (Rated for Div. 2) {1107} | PROGRAMMING | Educational Codeforces Round 59 Editorial | 1100 | |
| 3923 | Compression | dp implementation math number theory | Statement | D | Educational Codeforces Round 59 (Rated for Div. 2) {1107} | PROGRAMMING | Educational Codeforces Round 59 Editorial | 1800 | |
| 25415 | Divisors of Two Integers | brute force greedy math number theory | Statement | B | Codeforces Round 535 (Div. 3) {1108} | PROGRAMMING | 64751 | 1100 | |
| 1546 | Sasha and Interesting Fact from Graph Theory | brute force combinatorics dp math trees | Statement | D | Codeforces Round 539 (Div. 1) {1109} | PROGRAMMING | Codeforces Round #539 Editorial | 2600 | |
| 641 | Sasha and a Very Easy Test | data structures number theory | Statement | E | Codeforces Round 539 (Div. 1) {1109} | PROGRAMMING | Codeforces Round #539 Editorial | 2700 | |
| 10088 | Meaningless Operations | constructive algorithms math number theory | Statement | C | Codeforces Global Round 1 {1110} | PROGRAMMING | The Editorial of the First Codeforces Global Round | 1500 | |
| 8344 | Sasha and Magnetic Machines | greedy number theory | Statement | B | Codeforces Round 539 (Div. 2) {1113} | PROGRAMMING | Codeforces Round #539 Editorial | 1300 | |
| 7987 | Trailing Loves (or L'oeufs?) | brute force implementation math number theory | Statement | C | Codeforces Round 538 (Div. 2) {1114} | PROGRAMMING | Codeforces Round #538 (Div. 2) Editorial | 1700 | |
| 3259 | Arithmetic Progression | binary search interactive number theory probabilities | Statement | E | Codeforces Round 538 (Div. 2) {1114} | PROGRAMMING | Codeforces Round #538 (Div. 2) Editorial | 2100 | |
| 2559 | Please, another Queries on Array? | bitmasks data structures divide and conquer math number theory | Statement | F | Codeforces Round 538 (Div. 2) {1114} | PROGRAMMING | Codeforces Round #538 (Div. 2) Editorial | 2500 | |
| 14516 | Preparation for International Women's Day | math number theory | Statement | B | Codeforces Round 544 (Div. 3) {1133} | PROGRAMMING | Codeforces Round #544 (Div. 3) Editorial | 1300 | |
| 17279 | Zero Quantity Maximization | hashing math number theory | Statement | D | Codeforces Round 544 (Div. 3) {1133} | PROGRAMMING | Codeforces Round #544 (Div. 3) Editorial | 1500 | |
| 2246 | Cooperative Game | constructive algorithms interactive number theory | Statement | D | Codeforces Round 545 (Div. 1) {1137} | PROGRAMMING | Codeforces Round #545 – Editorial | 2500 | |
| 2794 | Steps to One | dp math number theory probabilities | Statement | D | Codeforces Round 548 (Div. 2) {1139} | PROGRAMMING | Codeforces Round #548 Editorial | 2300 | |
| 11709 | Nirvana | brute force math number theory | Statement | B | Codeforces Round 549 (Div. 2) {1143} | PROGRAMMING | Codeforces Round #549 Editorial | 1300 | |
| 4472 | Median String | bitmasks math number theory strings | Statement | E | Codeforces Round 550 (Div. 3) {1144} | PROGRAMMING | 66307 | 1900 | |
| 1228 | Frog Jumping | dfs and similar math number theory | Statement | D | Forethought Future Cup - Elimination Round {1146} | PROGRAMMING | 66639 | 2100 | |
| 614 | Gold Experience | constructive algorithms graphs math number theory probabilities | Statement | G | Codeforces Global Round 3 {1148} | PROGRAMMING | Codeforces Global Round 3 Editorial | 3100 | |
| 18158 | Prefix Sum Primes | constructive algorithms greedy math number theory | Statement | A | Codeforces Round 556 (Div. 1) {1149} | PROGRAMMING | 66783 | 1300 | |
| 7146 | Neko does Maths | brute force math number theory | Statement | C | Codeforces Round 554 (Div. 2) {1152} | PROGRAMMING | T | 1800 | |
| 3387 | Minimum Possible LCM | brute force greedy math number theory | Statement | G | Codeforces Round 552 (Div. 3) {1154} | PROGRAMMING | Codeforces Round #552 (Div. 3) Editorial | 2400 | |
| 9825 | Alarm Clocks Everywhere | math number theory | Statement | C | Educational Codeforces Round 63 (Rated for Div. 2) {1155} | PROGRAMMING | 66687 | 1300 | |
| 20229 | Almost All Divisors | math number theory | Statement | D | Codeforces Round 560 (Div. 3) {1165} | PROGRAMMING | Codeforces Round #560 (Div. 3) Editorial | 1600 | |
| 11973 | All the Vowels Please | constructive algorithms math number theory | Statement | B | Codeforces Round 561 (Div. 2) {1166} | PROGRAMMING | Codeforces Round #561 (Div. 2) Editorial | 1100 | |
| 3036 | The LCMs Must be Large | bitmasks brute force constructive algorithms math number theory | Statement | E | Codeforces Round 561 (Div. 2) {1166} | PROGRAMMING | Codeforces Round #561 (Div. 2) Editorial | 2000 | |
| 12854 | Ehab and a Special Coloring Problem | constructive algorithms number theory | Statement | C | Codeforces Round 563 (Div. 2) {1174} | PROGRAMMING | Codeforces round #563 editorial | 1300 | |
| 1834 | Ehab and the Expected GCD Problem | combinatorics dp math number theory | Statement | E | Codeforces Round 563 (Div. 2) {1174} | PROGRAMMING | Codeforces round #563 editorial | 2500 | |
| 5866 | Recover it! | dfs and similar graphs greedy number theory sortings | Statement | D | Codeforces Round 565 (Div. 3) {1176} | PROGRAMMING | 67598 | 1900 | |
| 7965 | Prime Graph | constructive algorithms greedy math number theory | Statement | D | Codeforces Global Round 4 {1178} | PROGRAMMING | E | 1600 | |
| 3461 | Product Oriented Recurrence | dp math matrices number theory | Statement | E | Codeforces Round 566 (Div. 2) {1182} | PROGRAMMING | 67614 | 2200 | |
| 426 | Maximum Sine | binary search data structures number theory | Statement | F | Codeforces Round 566 (Div. 2) {1182} | PROGRAMMING | 67614 | 2900 | |
| 6648 | Heidi Learns Hashing (Easy) | brute force math number theory | Statement | A1 | Helvetic Coding Contest 2019 online mirror (teams allowed, unrated) {1184} | PROGRAMMING | helvetic-coding-contest-2019-editorial.pdf | 1200 | |
| 1151 | Heidi Learns Hashing (Medium) | brute force number theory | Statement | A2 | Helvetic Coding Contest 2019 online mirror (teams allowed, unrated) {1184} | PROGRAMMING | helvetic-coding-contest-2019-editorial.pdf | 2100 | |
| 171 | Heidi Learns Hashing (Hard) | fft math number theory | Statement | A3 | Helvetic Coding Contest 2019 online mirror (teams allowed, unrated) {1184} | PROGRAMMING | helvetic-coding-contest-2019-editorial.pdf | 3100 | |
| 5269 | Count Pairs | math matrices number theory two pointers | Statement | B | Codeforces Round 572 (Div. 1) {1188} | PROGRAMMING | Editorial of Codeforces Round #572 | 2200 | |
| 171 | Tokitsukaze and Powers | number theory probabilities | Statement | F | Codeforces Round 573 (Div. 1) {1190} | PROGRAMMING | E | 3300 | |
| 1250 | Crossword Expert | combinatorics dp number theory probabilities two pointers | Statement | F | Educational Codeforces Round 68 (Rated for Div. 2) {1194} | PROGRAMMING | Разбор Educational Codeforces Round 68 | 2500 | |
| 8230 | Submarine in the Rybinsk Sea (easy edition) | combinatorics math number theory | Statement | D1 | Codeforces Round 574 (Div. 2) {1195} | PROGRAMMING | Разбор Codeforces Round #574 (Div. 2) | 1500 | |
| 4917 | Submarine in the Rybinsk Sea (hard edition) | combinatorics math number theory | Statement | D2 | Codeforces Round 574 (Div. 2) {1195} | PROGRAMMING | Разбор Codeforces Round #574 (Div. 2) | 1700 | |
| 1103 | GCD Groups 2 | greedy number theory probabilities | Statement | F | Codeforces Round 576 (Div. 1) {1198} | PROGRAMMING | E | 2900 | |
| 10684 | Round Corridor | math number theory | Statement | C | Codeforces Round 578 (Div. 2) {1200} | PROGRAMMING | Codeforces Round #578 (Div. 2) Editorial | 1500 | |
| 1193 | Graph Traveler | brute force data structures dfs and similar dp graphs implementation math number theory | Statement | F | Codeforces Round 578 (Div. 2) {1200} | PROGRAMMING | Codeforces Round #578 (Div. 2) Editorial | 2500 | |
| 2234 | Natasha, Sasha and the Prefix Sums | combinatorics dp math number theory | Statement | E | Codeforces Round 581 (Div. 2) {1204} | PROGRAMMING | 69244 | 2400 | |
| 973 | Polygons | greedy math number theory | Statement | G | Manthan, Codefest 19 (open for everyone, rated, Div. 1 + Div. 2) {1208} | PROGRAMMING | 69357 | 2700 | |
| 8583 | Koala and Lights | implementation math number theory | Statement | B | Codeforces Round 584 - Dasha Code Championship - Elimination Round (rated, open for everyone, Div. 1 + Div. 2) {1209} | PROGRAMMING | 69791 | 1300 | |
| 3658 | Kamil and Making a Stream | math number theory trees | Statement | C | Dasha Code Championship - SPb Finals Round (only for onsite-finalists) {1210} | PROGRAMMING | Dasha Code Championship Finals and Mirror Round 588 Editorial | 2100 | |
| 89 | King's Path | *special math trees | Statement | G | Kotlin Heroes: Episode 2 {1211} | PROGRAMMING | Kotlin Heroes: Episode 2 Editorial | 2500 | |
| 55 | Unusual Graph | *special graphs | Statement | I | Kotlin Heroes: Episode 2 {1211} | PROGRAMMING | Kotlin Heroes: Episode 2 Editorial | 3000 | |
| 10847 | Substring Game in the Lesson | games greedy strings | Statement | C | Codeforces Round 586 (Div. 1 + Div. 2) {1220} | PROGRAMMING | Codeforces Round #586 Editorial | 1300 | |
| 12183 | Multiplication Table | math number theory | Statement | B | Codeforces Round 586 (Div. 1 + Div. 2) {1220} | PROGRAMMING | Codeforces Round #586 Editorial | 1300 | |
| 4150 | Alex and Julian | bitmasks math number theory | Statement | D | Codeforces Round 586 (Div. 1 + Div. 2) {1220} | PROGRAMMING | Codeforces Round #586 Editorial | 1900 | |
| 385 | Wooden Raft | binary search math number theory | Statement | G | Technocup 2020 - Elimination Round 1 {1223} | PROGRAMMING | Сodeforces Round 591 (and Technocup 2020 — Elimination Round 1) Editorial | 3100 | |
| 10439 | Power Products | hashing math number theory | Statement | D | Technocup 2020 - Elimination Round 2 {1225} | PROGRAMMING | 70898 | 1900 | |
| 665 | To Make 1 | bitmasks constructive algorithms dp greedy number theory | Statement | G | Technocup 2020 - Elimination Round 2 {1225} | PROGRAMMING | 70898 | 3000 | |
| 9759 | Primes and Multiplication | math number theory | Statement | C | Codeforces Round 589 (Div. 2) {1228} | PROGRAMMING | 70162 | 1600 | |
| 28519 | Prime Subtraction | math number theory | Statement | A | Educational Codeforces Round 74 (Rated for Div. 2) {1238} | PROGRAMMING | Educational Codeforces Round 74 Editorial | 900 | |
| 7820 | Ivan the Fool and the Probability Theory | combinatorics dp math | Statement | A | Codeforces Round 594 (Div. 1) {1239} | PROGRAMMING | Editorial of Codeforces Round #594 (on the problems of Moscow Team Olympiad) | 1700 | |
| 13324 | Tile Painting | constructive algorithms math number theory | Statement | A | Codeforces Round 599 (Div. 1) {1242} | PROGRAMMING | Codeforces Round #599 Editorial | 1500 | |
| 9599 | 0-1 MST | dfs and similar dsu graphs sortings | Statement | B | Codeforces Round 599 (Div. 1) {1242} | PROGRAMMING | Codeforces Round #599 Editorial | 1900 | |
| 8423 | The Football Season | brute force math number theory | Statement | C | Codeforces Round 592 (Div. 2) {1244} | PROGRAMMING | Codeforces Round #592 (Div. 2) Tutorial | 1900 | |
| 14978 | Good ol' Numbers Coloring | math number theory | Statement | A | Codeforces Round 597 (Div. 2) {1245} | PROGRAMMING | Codeforces Round #597 (Div. 2) Editorial | 1000 | |
| 5060 | Send Boxes to Alice (Easy Version) | constructive algorithms greedy math number theory ternary search two pointers | Statement | B1 | Codeforces Round 601 (Div. 1) {1254} | PROGRAMMING | Codeforces Round #601 Editorial | 2000 | |
| 3548 | Send Boxes to Alice (Hard Version) | constructive algorithms greedy math number theory ternary search two pointers | Statement | B2 | Codeforces Round 601 (Div. 1) {1254} | PROGRAMMING | Codeforces Round #601 Editorial | 2100 | |
| 798 | Divisor Set | divide and conquer fft greedy math number theory | Statement | G | Educational Codeforces Round 76 (Rated for Div. 2) {1257} | PROGRAMMING | Educational Codeforces Round 76 Editorial | 2700 | |
| 8922 | Infinite Fence | greedy math number theory | Statement | C | Educational Codeforces Round 77 (Rated for Div. 2) {1260} | PROGRAMMING | Educational Codeforces Round 77 Editorial | 1700 | |
| 14740 | Everyone is a Winner! | binary search math meet-in-the-middle number theory | Statement | C | Codeforces Round 603 (Div. 2) {1263} | PROGRAMMING | Разбор Codeforces Round #603 (Div. 2) | 1400 | |
| 1131 | Beautiful Fibonacci Problem | constructive algorithms number theory | Statement | F | Codeforces Round 604 (Div. 1) {1264} | PROGRAMMING | 71995 | 3600 | |
| 10107 | Diverse Matrix | constructive algorithms greedy math number theory | Statement | C | Codeforces Global Round 6 {1266} | PROGRAMMING | Codeforces Global Round 6 Editorial | 1400 | |
| 17336 | Make Them Odd | greedy number theory | Statement | B | Codeforces Round 606 (Div. 2, based on Technocup 2020 Elimination Round 4) {1277} | PROGRAMMING | Technocup 2020 — Elimination Round 4 + Codeforces Round 606: Editorial | 1200 | |
| 2706 | Cards | combinatorics dp math number theory probabilities | Statement | F | Educational Codeforces Round 78 (Rated for Div. 2) {1278} | PROGRAMMING | Educational Codeforces Round 78 Editorial | 2600 | |
| 28790 | Fadi and LCM | brute force math number theory | Statement | C | Codeforces Round 613 (Div. 2) {1285} | PROGRAMMING | Codeforces Round #613 (Div. 2) Editorial | 1400 | |
| 1396 | Classical? | binary search combinatorics number theory | Statement | F | Codeforces Round 613 (Div. 2) {1285} | PROGRAMMING | Codeforces Round #613 (Div. 2) Editorial | 2800 | |
| 1052 | Chaotic V. | dp graphs greedy math number theory trees | Statement | D | Codeforces Round 614 (Div. 1) {1292} | PROGRAMMING | 1750.0 | Codeforces Round #614 Editorial | 2700 |
| 48366 | Product of Three Numbers | greedy math number theory | Statement | C | Codeforces Round 615 (Div. 3) {1294} | PROGRAMMING | Codeforces Round #615 (Div. 3) Editorial | 1300 | |
| 10415 | Same GCDs | math number theory | Statement | D | Educational Codeforces Round 81 (Rated for Div. 2) {1295} | PROGRAMMING | Educational Codeforces Round 81 Editorial | 1800 | |
| 51 | Amazing bitset | Statement | E | AIM Tech Poorly Prepared Contest (unrated, funny, Div. 1 preferred) {1302} | PROGRAMMING | 73599 | |||
| 19663 | Kuroni and Impossible Calculation | brute force combinatorics math number theory | Statement | C | Ozon Tech Challenge 2020 (Div.1 + Div.2, Rated, T-shirts + prizes!) {1305} | PROGRAMMING | 1250.0 | Ozon Tech Challenge 2020 Editorial | 1600 |
| 3333 | Kuroni and the Punishment | math number theory probabilities | Statement | F | Ozon Tech Challenge 2020 (Div.1 + Div.2, Rated, T-shirts + prizes!) {1305} | PROGRAMMING | 2500.0 | Ozon Tech Challenge 2020 Editorial | 2500 |
| 214 | Bad Cryptography | math number theory | Statement | F | VK Cup 2019-2020 - Elimination Round (Engine) {1310} | PROGRAMMING | 3500.0 | VK Cup 2019-2020 - Elimination Round (Engine) and Codeforces Round #623 | 3300 |
| 18543 | Adding Powers | bitmasks greedy implementation math number theory ternary search | Statement | C | Educational Codeforces Round 83 (Rated for Div. 2) {1312} | PROGRAMMING | 74640 | ||
| 27679 | Two Regular Polygons | geometry math number theory | Statement | A | Educational Codeforces Round 83 (Rated for Div. 2) {1312} | PROGRAMMING | 74640 | ||
| 2786 | Instant Noodles | graphs hashing math number theory | Statement | C | Codeforces Round 626 (Div. 1, based on Moscow Open Olympiad in Informatics) {1322} | PROGRAMMING | 1500.0 | Codeforces Round #626 Editorial | |
| 27469 | Yet Another Tetris Problem | implementation number theory | Statement | A | Codeforces Round 627 (Div. 3) {1324} | PROGRAMMING | Codeforces Round #627 (Div. 3) Editorial | ||
| 13833 | Ehab the Xorcist | bitmasks constructive algorithms greedy number theory | Statement | D | Codeforces Round 628 (Div. 2) {1325} | PROGRAMMING | 1750.0 | 74235 | 1700 |
| 2416 | Ehab's REAL Number Theory Problem | brute force dfs and similar graphs number theory shortest paths | Statement | E | Codeforces Round 628 (Div. 2) {1325} | PROGRAMMING | 2500.0 | 74235 | 2700 |
| 47052 | EhAb AnD gCd | constructive algorithms greedy number theory | Statement | A | Codeforces Round 628 (Div. 2) {1325} | PROGRAMMING | 500.0 | 74235 | 800 |
| 32982 | Bad Ugly Numbers | constructive algorithms number theory | Statement | A | Codeforces Global Round 7 {1326} | PROGRAMMING | 500.0 | 74961 | 1000 |
| 3593 | Infinite Path | brute force dfs and similar graphs math number theory | Statement | D | Educational Codeforces Round 84 (Rated for Div. 2) {1327} | PROGRAMMING | Educational Codeforces Round 84 Editorial | 2200 | |
| 7170 | Limericks | math number theory | Statement | B | April Fools Day Contest 2020 {1331} | PROGRAMMING | April Fools Day Contest 2020: editorial | ||
| 19908 | Exercising Walk | greedy implementation math | Statement | A | Codeforces Round 630 (Div. 2) {1332} | PROGRAMMING | 500.0 | Codeforces Round #630 Editorial | 1200 |
| 19316 | Composite Coloring | brute force constructive algorithms greedy math number theory | Statement | B | Codeforces Round 630 (Div. 2) {1332} | PROGRAMMING | 1000.0 | Codeforces Round #630 Editorial | 1500 |
| 1194 | Independent Set | dfs and similar dp trees | Statement | F | Codeforces Round 630 (Div. 2) {1332} | PROGRAMMING | 2250.0 | Codeforces Round #630 Editorial | 2500 |
| 4641 | Kate and imperfection | greedy implementation math number theory sortings two pointers | Statement | F | Codeforces Round 632 (Div. 2) {1333} | PROGRAMMING | 2500.0 | Codeforces Round #632 (Div. 2) editorial | |
| 3230 | Divisor Paths | combinatorics graphs greedy math number theory | Statement | E | Educational Codeforces Round 85 (Rated for Div. 2) {1334} | PROGRAMMING | Educational Codeforces Round 85 Editorial | ||
| 15097 | Yet Another Counting Problem | math number theory | Statement | C | Educational Codeforces Round 86 (Rated for Div. 2) {1342} | PROGRAMMING | 76633 | 1700 | |
| 16605 | Hilbert's Hotel | math number theory sortings | Statement | A | Codeforces Round 639 (Div. 1) {1344} | PROGRAMMING | 500.0 | Codeforces Round #639 Editorial | 1600 |
| 153 | Two IP Cameras | *special math number theory | Statement | G | Kotlin Heroes: Episode 4 {1346} | PROGRAMMING | Kotlin Heroes: Episode 4 — Editorial | 2300 | |
| 22424 | Orac and LCM | data structures math number theory | Statement | A | Codeforces Round 641 (Div. 1) {1349} | PROGRAMMING | 500.0 | Codeforces Round #641 Editorial | 1600 |
| 30653 | Orac and Models | dp math number theory | Statement | B | Codeforces Round 641 (Div. 2) {1350} | PROGRAMMING | 1000.0 | Codeforces Round #641 Editorial | 1400 |
| 27543 | Orac and Factors | math | Statement | A | Codeforces Round 641 (Div. 2) {1350} | PROGRAMMING | 500.0 | Codeforces Round #641 Editorial | 900 |
| 984 | Guess Divisors Count | constructive algorithms interactive number theory | Statement | F | Codeforces Round 643 (Div. 2) {1355} | PROGRAMMING | 3000.0 | Codeforces Round #643 (Div. 2) Editorial | 2600 |
| 6849 | Modular Stability | combinatorics math number theory | Statement | E | Educational Codeforces Round 88 (Rated for Div. 2) {1359} | PROGRAMMING | Educational Codeforces Round 88 Editorial | 2000 | |
| 44806 | Buying Shovels | math number theory | Statement | D | Codeforces Round 644 (Div. 3) {1360} | PROGRAMMING | Codeforces Round #644 (Div. 3) Editorial | 1300 | |
| 8396 | A/B Matrix | constructive algorithms flows greedy math number theory | Statement | G | Codeforces Round 644 (Div. 3) {1360} | PROGRAMMING | Codeforces Round #644 (Div. 3) Editorial | 1900 | |
| 31859 | XXXXX | brute force data structures number theory two pointers | Statement | A | Codeforces Round 649 (Div. 2) {1364} | PROGRAMMING | 750.0 | Codeforces round #649 editorial | 1200 |
| 12592 | Two Divisors | constructive algorithms math number theory | Statement | D | Educational Codeforces Round 89 (Rated for Div. 2) {1366} | PROGRAMMING | Educational Codeforces Round 89 Editorial | ||
| 5923 | Necklace Assembly | binary search brute force dp greedy number theory | Statement | E | Codeforces Round 650 (Div. 3) {1367} | PROGRAMMING | Codeforces Round #650 (Div. 3) Editorial | ||
| 25306 | GCD Compression | brute force constructive algorithms math number theory | Statement | B | Codeforces Round 651 (Div. 2) {1370} | PROGRAMMING | 1000.0 | Editorial — Codeforces Round #651 | |
| 66586 | Maximum GCD | brute force greedy implementation number theory | Statement | A | Codeforces Round 651 (Div. 2) {1370} | PROGRAMMING | 500.0 | Editorial — Codeforces Round #651 | |
| 27528 | Number Game | games math number theory | Statement | C | Codeforces Round 651 (Div. 2) {1370} | PROGRAMMING | 1500.0 | Editorial — Codeforces Round #651 | |
| 2541 | Asterism (Hard Version) | binary search math number theory sortings | Statement | E2 | Codeforces Round 654 (Div. 2) {1371} | PROGRAMMING | 1250.0 | Codeforces Round #654 (Div. 2) Editorial | |
| 5546 | Asterism (Easy Version) | brute force combinatorics implementation math number theory sortings | Statement | E1 | Codeforces Round 654 (Div. 2) {1371} | PROGRAMMING | 1500.0 | Codeforces Round #654 (Div. 2) Editorial | |
| 37844 | Omkar and Last Class of Math | constructive algorithms greedy math number theory | Statement | B | Codeforces Round 655 (Div. 2) {1372} | PROGRAMMING | 1000.0 | Codeforces Round #655 Editorial | 1300 |
| 2992 | Sum of Digits | brute force constructive algorithms dp greedy math number theory | Statement | E | Educational Codeforces Round 90 (Rated for Div. 2) {1373} | PROGRAMMING | Educational Codeforces Round 90 Editorial | ||
| 282 | Cubic Lattice | geometry math matrices number theory | Statement | I | Codeforces Global Round 9 {1375} | PROGRAMMING | 4000.0 | 79731 | |
| 13222 | Dubious Cyrpto | binary search brute force math number theory | Statement | B | Codeforces Round 657 (Div. 2) {1379} | PROGRAMMING | 750.0 | Codeforces Round #657 Editorial | 1500 |
| 12352 | Acacius and String | brute force implementation strings | Statement | A | Codeforces Round 657 (Div. 2) {1379} | PROGRAMMING | 500.0 | Codeforces Round #657 Editorial | 1500 |
| 26045 | Captain Flint and Crew Recruitment | brute force math number theory | Statement | A | Codeforces Round 660 (Div. 2) {1388} | PROGRAMMING | 750.0 | Codeforces Round #660 Editorial | 800 |
| 51384 | LCM Problem | constructive algorithms greedy math number theory | Statement | A | Educational Codeforces Round 92 (Rated for Div. 2) {1389} | PROGRAMMING | 80809 | ||
| 3763 | Calendar Ambiguity | math number theory | Statement | E | Educational Codeforces Round 92 (Rated for Div. 2) {1389} | PROGRAMMING | 80809 | ||
| 16817 | Multiples of Length | constructive algorithms greedy number theory | Statement | A | Codeforces Round 666 (Div. 1) {1396} | PROGRAMMING | 500.0 | Codeforces Round #666 — Editorial | |
| 15551 | Power Sequence | binary search brute force math number theory ternary search | Statement | B | Codeforces Round 666 (Div. 2) {1397} | PROGRAMMING | 1000.0 | Codeforces Round #666 — Editorial | |
| 1335 | Running Competition | bitmasks fft math number theory | Statement | G | Educational Codeforces Round 93 (Rated for Div. 2) {1398} | PROGRAMMING | Educational Codeforces Round 93 Editorial | ||
| 1237 | x-prime Substrings | bitmasks dp greedy number theory string suffix structures strings | Statement | F | Educational Codeforces Round 94 (Rated for Div. 2) {1400} | PROGRAMMING | 81942 | ||
| 10736 | Maximum Distributed Tree | constructive algorithms dfs and similar greedy math number theory sortings trees | Statement | D | Codeforces Round 665 (Div. 2) {1401} | PROGRAMMING | 1750.0 | Codeforces Round #665 (Div. 2) Editorial | |
| 27285 | Mere Array | constructive algorithms math number theory number theory sortings sortings | Statement | C | Codeforces Round 665 (Div. 2) {1401} | PROGRAMMING | 1500.0 | Codeforces Round #665 (Div. 2) Editorial | |
| 28781 | Distance and Axis | math number theory | Statement | A | Codeforces Round 665 (Div. 2) {1401} | PROGRAMMING | 500.0 | Codeforces Round #665 (Div. 2) Editorial | |
| 1303 | Game of Pairs | constructive algorithms dfs and similar interactive math number theory | Statement | D | Codeforces Round 668 (Div. 1) {1404} | PROGRAMMING | 2250.0 | Codeforces Round #668 Editorial | |
| 1930 | Deleting Numbers | binary search brute force interactive number theory | Statement | E | Codeforces Round 670 (Div. 2) {1406} | PROGRAMMING | 2750.0 | Codeforces Round #670 (Div. 2) Editorial | |
| 18218 | Big Vova | brute force greedy math number theory | Statement | B | Codeforces Round 669 (Div. 2) {1407} | PROGRAMMING | 1000.0 | Codeforces Round #669 Editorial | |
| 32342 | Fair Numbers | brute force number theory | Statement | B | Technocup 2021 - Elimination Round 3 {1411} | PROGRAMMING | 1000.0 | Technocup 2021 Elimination Round 3 and Round #692 (Div. 1 + Div. 2) Editorial | |
| 518 | Equal Product | data structures math number theory two pointers | Statement | F | Educational Codeforces Round 95 (Rated for Div. 2) {1418} | PROGRAMMING | Unofficial Editorial for Educational Round 95 (Div. 2) | ||
| 3544 | Decryption | bitmasks constructive algorithms implementation math number theory | Statement | E | Codeforces Round 671 (Div. 2) {1419} | PROGRAMMING | 2250.0 | Codeforces Round #671 Editorial | |
| 1406 | Boring Queries | data structures number theory trees | Statement | F | Codeforces Round 675 (Div. 2) {1422} | PROGRAMMING | 2750.0 | Codeforces Round #675 (Div. 2) Editorial | |
| 5490 | Lonely Numbers | binary search math number theory | Statement | K | Bubble Cup 13 - Finals [Online Mirror, unrated, Div. 1] {1423} | PROGRAMMING | FinalsEditorial2020.pdf | ||
| 1685 | Xum | bitmasks constructive algorithms math number theory | Statement | E | Codeforces Global Round 11 {1427} | PROGRAMMING | 1500.0 | Editorial of Global Round 11 | 2500 |
| 693 | Sum Over Subsets | combinatorics math number theory | Statement | F | Codeforces Round 678 (Div. 2) {1436} | PROGRAMMING | 3000.0 | Codeforces Round #678 (Div. 2). Editorial | |
| 173 | Differentiating Games | games interactive | Statement | F | Codeforces Round 681 (Div. 1, based on VK Cup 2019-2020 - Final) {1442} | PROGRAMMING | 2500.0 | 84298 | |
| 14608 | Division | math number theory | Statement | A | Codeforces Round 680 (Div. 1, based on Moscow Team Olympiad) {1444} | PROGRAMMING | 500.0 | Codeforces Round #680 Editorial | |
| 22530 | Number into Sequence | constructive algorithms math number theory | Statement | D | Codeforces Round 686 (Div. 3) {1454} | PROGRAMMING | Codeforces Round #686 (Div. 3) Editorial | ||
| 26373 | Row GCD | math number theory | Statement | A | Codeforces Round 691 (Div. 1) {1458} | PROGRAMMING | 500.0 | Codeforces Round #691 Editorial (finished) | |
| 18387 | Add to Neighbour and Remove | greedy math number theory | Statement | D | Codeforces Round 690 (Div. 3) {1462} | PROGRAMMING | Codeforces Round #690 (Div. 3) Editorial | ||
| 4246 | Full Turn | geometry number theory | Statement | F | 2020-2021 ICPC, NERC, Southern and Volga Russian Regional Contest (Online Mirror, ICPC Rules) {1468} | PROGRAMMING | Tutorial (PDF) | ||
| 382 | Prime Divisors Selection | greedy math number theory | Statement | L | 2020-2021 ICPC, NERC, Southern and Volga Russian Regional Contest (Online Mirror, ICPC Rules) {1468} | PROGRAMMING | Tutorial (PDF) | ||
| 10282 | Ceil Divisions | brute force constructive algorithms math number theory | Statement | D | Educational Codeforces Round 101 (Rated for Div. 2) {1469} | PROGRAMMING | Educational Codeforces Round 101 Editorial | ||
| 6819 | Strange Definition | bitmasks brute force data structures graphs math number theory | Statement | B | Codeforces Round 694 (Div. 1) {1470} | PROGRAMMING | 750.0 | 86464 | |
| 40402 | Strange Partition | greedy math number theory | Statement | A | Codeforces Round 694 (Div. 2) {1471} | PROGRAMMING | 500.0 | Codeforces Round #694 Editorial | |
| 42403 | Different Divisors | binary search constructive algorithms greedy math number theory | Statement | B | Codeforces Round 696 (Div. 2) {1474} | PROGRAMMING | 1000.0 | Codeforces Round #696 Editorial | |
| 90781 | Odd Divisor | bitmasks math number theory | Statement | A | Codeforces Round 697 (Div. 3) {1475} | PROGRAMMING | Codeforces Round #697 (Div. 3) Editorial | ||
| 8006 | Strange Beauty | dfs and similar dp math number theory | Statement | G | Codeforces Round 697 (Div. 3) {1475} | PROGRAMMING | Codeforces Round #697 (Div. 3) Editorial | ||
| 6613 | Nezzar and Board | constructive algorithms math number theory | Statement | A | Codeforces Round 698 (Div. 1) {1477} | PROGRAMMING | 500.0 | 87294 | 1800 |
| 432 | School Clubs | dp fft math number theory probabilities | Statement | E | Codeforces Round 700 (Div. 1) {1479} | PROGRAMMING | 4000.0 | Editorial of Codeforces Round #700 | |
| 11181 | Floor and Mod | binary search brute force data structures math number theory | Statement | C | Codeforces Round 701 (Div. 2) {1485} | PROGRAMMING | 1500.0 | Editorial of Codeforces Round #701 (Div. 2) | 1700 |
| 5718 | Multiples and Power Differences | constructive algorithms math number theory | Statement | D | Codeforces Round 701 (Div. 2) {1485} | PROGRAMMING | 1750.0 | Editorial of Codeforces Round #701 (Div. 2) | 2200 |
| 20869 | Pythagorean Triples | binary search math number theory | Statement | D | Educational Codeforces Round 104 (Rated for Div. 2) {1487} | PROGRAMMING | 87873 | ||
| 30166 | Cat Cycle | math number theory | Statement | B | Educational Codeforces Round 104 (Rated for Div. 2) {1487} | PROGRAMMING | 87873 | ||
| 137 | Painting Numbers | *special data structures greedy number theory | Statement | G | Kotlin Heroes: Episode 6 {1488} | PROGRAMMING | 88522 | ||
| 525 | Enchanted Matrix | bitmasks interactive number theory | Statement | F | Codeforces Round 705 (Div. 2) {1493} | PROGRAMMING | 3250.0 | Codeforces Round #705 (Div.2) Editorial | |
| 5883 | GCD of an Array | data structures math number theory sortings two pointers | Statement | D | Codeforces Round 705 (Div. 2) {1493} | PROGRAMMING | 2250.0 | Codeforces Round #705 (Div.2) Editorial | |
| 9176 | Square-free division (easy version) | data structures dp greedy math number theory | Statement | E1 | Codeforces Round 708 (Div. 2) {1497} | PROGRAMMING | 1500.0 | Codeforces Round #708 Editorial | 1700 |
| 1957 | Square-free division (hard version) | data structures dp greedy hashing math number theory | Statement | E2 | Codeforces Round 708 (Div. 2) {1497} | PROGRAMMING | 1500.0 | Codeforces Round #708 Editorial | 2500 |
| 7252 | The Number of Pairs | math number theory | Statement | D | Educational Codeforces Round 106 (Rated for Div. 2) {1499} | PROGRAMMING | Educational Codeforces Round 106 Editorial | ||
| 2365 | Two chandeliers | binary search brute force chinese remainder theorem math number theory | Statement | B | Codeforces Round 707 (Div. 1, based on Moscow Open Olympiad in Informatics) {1500} | PROGRAMMING | 750.0 | Codeforces Round #707 Editorial | 2200 |
| 2134 | Digits | brute force dp math number theory | Statement | D | 2020-2021 ICPC, NERC, Northern Eurasia Onsite (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {1510} | PROGRAMMING | nerc-2020-offline-tutorial.pdf | ||
| 24906 | GCD Length | constructive algorithms math number theory | Statement | B | Educational Codeforces Round 107 (Rated for Div. 2) {1511} | PROGRAMMING | 89634 | ||
| 9623 | Short Task | brute force dp math number theory | Statement | G | Codeforces Round 713 (Div. 3) {1512} | PROGRAMMING | Codeforces Round #713 (Div. 3) Editorial | ||
| 6674 | GCD and MST | constructive algorithms data structures dsu graphs implementation number theory sortings | Statement | D | Divide by Zero 2021 and Codeforces Round 714 (Div. 2) {1513} | PROGRAMMING | 2000.0 | Divide by Zero 2021 and Codeforces Round #714 (Div. 2) Editorial | |
| 18754 | Product 1 Modulo N | constructive algorithms math number theory | Statement | C | Codeforces Round 716 (Div. 2) {1514} | PROGRAMMING | 1500.0 | Codeforces round #716 editorial | |
| 25471 | Perfectly Imperfect Array | math number theory | Statement | A | Codeforces Round 716 (Div. 2) {1514} | PROGRAMMING | 500.0 | Codeforces round #716 editorial | |
| 1413 | Phoenix and Odometers | dfs and similar graphs math number theory | Statement | G | Codeforces Global Round 14 {1515} | PROGRAMMING | 3500.0 | Editorial |