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1503 Searching Rectangles binary search constructive algorithms interactive Statement B Codeforces Round 371 (Div. 1) {713} PROGRAMMING Codeforces Round #371 Editorial 2200
219 Verifying Kingdom binary search divide and conquer interactive trees Statement E VK Cup 2017 - Round 2 {772} PROGRAMMING VK Cup Round 2 + Codeforces Round #409 Tutorial 3200
1772 Glad to see you! binary search interactive Statement B Codeforces Round 415 (Div. 1) {809} PROGRAMMING 52099 2200
1346 The penguin's game binary search constructive algorithms interactive Statement E Codeforces Round 427 (Div. 2) {835} PROGRAMMING 2400
2036 Mahmoud and Ehab and the binary string binary search divide and conquer interactive Statement D Codeforces Round 435 (Div. 2) {862} PROGRAMMING Codeforces round #435 editorial 2000
2294 Ithea Plays With Chtholly binary search constructive algorithms games greedy interactive Statement B Codeforces Round 449 (Div. 1) {896} PROGRAMMING Codeforces Round #449 Editorial 2000
527 Guess two numbers binary search interactive Statement C Codeforces Round 497 (Div. 1) {1007} PROGRAMMING Editorial for Codeforces Round #497 by Skyglow 2800
6370 Rocket binary search interactive Statement B Codeforces Round 499 (Div. 1) {1010} PROGRAMMING 60851 1800
2110 The hat binary search interactive Statement B Codeforces Round 503 (by SIS, Div. 1) {1019} PROGRAMMING 61161 2200
787 Hidden Bipartite Graph binary search constructive algorithms dfs and similar graphs interactive Statement E Lyft Level 5 Challenge 2018 - Elimination Round {1033} PROGRAMMING The Lyft Level 5 Challenge 2018 Elimination Round (Div. 1 + Div. 2) Editorial 2700
2582 Subway Pursuit binary search interactive probabilities Statement B Codeforces Round 507 (Div. 1, based on Olympiad of Metropolises) {1039} PROGRAMMING 61668 2100
3275 Dwarves, Hats and Extrasensory Abilities binary search constructive algorithms geometry interactive Statement C Codeforces Round 516 (Div. 1, by Moscow Team Olympiad) {1063} PROGRAMMING 1900
3521 Game with modulo binary search constructive algorithms interactive Statement B Codeforces Round 534 (Div. 1) {1103} PROGRAMMING Codeforces Round #534 — Editorial 2000
3181 Arithmetic Progression binary search interactive number theory probabilities Statement E Codeforces Round 538 (Div. 2) {1114} PROGRAMMING Codeforces Round #538 (Div. 2) Editorial 2100
565 Legendary Tree binary search interactive trees Statement E Codeforces Round 542 [Alex Lopashev Thanks-Round] (Div. 1) {1129} PROGRAMMING 65520 3000
1754 Serval and Snake binary search brute force interactive Statement E Codeforces Round 551 (Div. 2) {1153} PROGRAMMING Editorial 2100
193 Strange device binary search interactive math trees Statement E Codeforces Round 559 (Div. 1) {1158} PROGRAMMING 66993 3300
92 Шардирование постов *special binary search interactive Statement F VK Cup 2019 - Квалификация (Engine) {1275} PROGRAMMING 3000.0
952 Find a Gift binary search interactive probabilities Statement G Educational Codeforces Round 87 (Rated for Div. 2) {1354} PROGRAMMING 77593 2600
4405 Guess The Maximums binary search divide and conquer implementation interactive math Statement D Codeforces Round 646 (Div. 2) {1363} PROGRAMMING 2000.0 78202 2100
1779 The Hidden Pair (Easy Version) binary search dfs and similar graphs interactive shortest paths trees Statement F1 Codeforces Round 651 (Div. 2) {1370} PROGRAMMING 2000.0 Editorial — Codeforces Round #651
1662 The Hidden Pair (Hard Version) binary search dfs and similar graphs interactive shortest paths trees Statement F2 Codeforces Round 651 (Div. 2) {1370} PROGRAMMING 1250.0 Editorial — Codeforces Round #651
349 Colors *special binary search constructive algorithms interactive Statement A Baltic Olympiad in Informatics 2020, Day 1 (IOI, Unofficial Mirror Contest, Unrated) {1386} PROGRAMMING T
312 The Potion of Great Power *special binary search data structures graphs interactive sortings two pointers Statement A Central-European Olympiad in Informatics, CEOI 2020, Day 2 (IOI, Unofficial Mirror Contest, Unrated) {1403} PROGRAMMING CEOI 2020 Online Mirror — Day 2 Tutorial
1864 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
127 Rotary Laser Lock binary search interactive Statement H Codeforces Raif Round 1 (Div. 1 + Div. 2) {1428} PROGRAMMING 4000.0 Codeforces Raif Round 1 Editorial
232 The Riddle of the Sphinx binary search data structures data structures interactive Statement I Good Bye 2020 {1466} PROGRAMMING 4000.0 Good Bye 2020 Editorial
1436 Strange Shuffle binary search brute force constructive algorithms interactive probabilities Statement C Codeforces Round 694 (Div. 1) {1470} PROGRAMMING 1000.0 86464
13055 Searching Local Minimum binary search interactive ternary search Statement A Codeforces Round 700 (Div. 1) {1479} PROGRAMMING 500.0 Editorial of Codeforces Round #700
344 Vabank binary search interactive Statement G Технокубок 2021 - Финал {1482} PROGRAMMING 3500.0 Technocup 2021: Final Round and Codeforces Round #709 — tutorial
41 Vabank binary search interactive Statement E Codeforces Round 709 (Div. 1, based on Technocup 2021 Final Round) {1483} PROGRAMMING 2500.0 Technocup 2021: Final Round and Codeforces Round #709 — tutorial
14200 Guessing the Greatest (easy version) binary search interactive Statement C1 Codeforces Round 703 (Div. 2) {1486} PROGRAMMING 750.0 Codeforces Round #703 (Div. 2) Editorial
9931 Guessing the Greatest (hard version) binary search interactive Statement C2 Codeforces Round 703 (Div. 2) {1486} PROGRAMMING 750.0 Codeforces Round #703 (Div. 2) Editorial
1130 Magnets binary search constructive algorithms interactive Statement F Codeforces Global Round 13 {1491} PROGRAMMING 2000.0 Codeforces Global Round 13 Editorial
695 Baby Ehab's Hyper Apartment binary search graphs interactive sortings Statement E Codeforces Round 716 (Div. 2) {1514} PROGRAMMING 2500.0 Codeforces round #716 editorial
3332 Guess the K-th Zero (Hard version) binary search data structures interactive Statement F2 Codeforces Round 719 (Div. 3) {1520} PROGRAMMING Editorial
14324 Guess the K-th Zero (Easy version) binary search interactive Statement F1 Codeforces Round 719 (Div. 3) {1520} PROGRAMMING Editorial
3059 Gold Transfer binary search data structures greedy interactive trees Statement E Educational Codeforces Round 110 (Rated for Div. 2) {1535} PROGRAMMING 91481
458 Guess the Perimeter binary search interactive number theory Statement H Codeforces Global Round 15 {1552} PROGRAMMING 2750.0 Editorial of Global Round 15
3983 Guess the Permutation binary search combinatorics interactive math Statement D Technocup 2022 - Elimination Round 2 {1584} PROGRAMMING 1500.0 Editorial for Technocup 2022 — Elimination Round 2 and Codeforces Round #755 (Div. 1, Div. 2) 2000
2551 Hemose in ICPC ? binary search dfs and similar divide and conquer interactive math number theory trees Statement D Codeforces Round 746 (Div. 2) {1592} PROGRAMMING 2000.0 95583
3777 Interacdive Problem binary search constructive algorithms interactive Statement F Codeforces Round 764 (Div. 3) {1624} PROGRAMMING Codeforces Round #764 (Div. 3) Editorial
2514 notepad.exe binary search constructive algorithms greedy interactive Statement E Codeforces Global Round 20 {1672} PROGRAMMING 1500.0 Global Round 20 Editorial 2200
4982 Guess The String binary search brute force constructive algorithms dsu interactive Statement D Educational Codeforces Round 130 (Rated for Div. 2) {1697} PROGRAMMING 103835
12020 Fixed Point Guessing binary search constructive algorithms interactive Statement D Codeforces Round 803 (Div. 2) {1698} PROGRAMMING 1500.0 Codeforces Round #803 (Div. 2) Editorial
1688 Joking (Easy Version) binary search bitmasks constructive algorithms interactive ternary search Statement E1 Codeforces Global Round 23 {1746} PROGRAMMING 2000.0 Codeforces Global Round 23 Editorial
697 Doremy's Perfect DS Class (Easy Version) binary search interactive Statement G1 Codeforces Global Round 24 {1764} PROGRAMMING 2000.0 Codeforces Global Round 24 Editorial
636 Doremy's Perfect DS Class (Medium Version) binary search interactive Statement G2 Codeforces Global Round 24 {1764} PROGRAMMING 500.0 Codeforces Global Round 24 Editorial
558 Doremy's Perfect DS Class (Hard Version) binary search interactive Statement G3 Codeforces Global Round 24 {1764} PROGRAMMING 500.0 Codeforces Global Round 24 Editorial
486 Hot and Cold binary search interactive Statement H 2022-2023 ICPC, NERC, Northern Eurasia Onsite (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {1773} PROGRAMMING 2600
5814 Bit Guessing Game binary search bitmasks interactive Statement D Codeforces Round 846 (Div. 2) {1780} PROGRAMMING 1500.0 111841
16582 Interview binary search implementation interactive Statement E Codeforces Round 859 (Div. 4) {1807} PROGRAMMING 114143
379 Stuck Conveyor binary search interactive Statement F Codeforces Round 877 (Div. 2) {1838} PROGRAMMING 3000.0 Codeforces Round #877 (Div. 2) Editorial
492 Good Colorings binary search constructive algorithms graphs interactive Statement E Codeforces Round 905 (Div. 1) {1887} PROGRAMMING 2000.0 Codeforces Round #905 (Div. 1, Div. 2, Div. 3) Editorial
2053 ace5 and Task Order binary search divide and conquer implementation interactive probabilities sortings Statement E Codeforces Round 922 (Div. 2) {1918} PROGRAMMING 2500.0 Codeforces Round #922 (Div. 2) Editorial
1135 Catch the Mole(Easy Version) binary search constructive algorithms data structures interactive trees Statement E1 Codeforces Round 960 (Div. 2) {1990} PROGRAMMING 2000.0 Video Tutorial
1098 Catch the Mole(Hard Version) binary search data structures dfs and similar interactive trees Statement E2 Codeforces Round 960 (Div. 2) {1990} PROGRAMMING 750.0 Video Tutorial
14443 Ruler (easy version) binary search interactive ternary search Statement G1 Codeforces Round 964 (Div. 4) {1999} PROGRAMMING Video Tutorial
10934 Ruler (hard version) binary search interactive ternary search Statement G2 Codeforces Round 964 (Div. 4) {1999} PROGRAMMING Video Tutorial
12741 Guess The Tree binary search brute force greedy interactive trees Statement C Codeforces Round 967 (Div. 2) {2001} PROGRAMMING 1500.0 Video Tutorial
3984 Asesino (Easy Version) binary search constructive algorithms implementation interactive Statement D1 Codeforces Round 978 (Div. 2) {2022} PROGRAMMING 1750.0 Codeforces Round 978 (Div 2) Editorial
449 Penchick and Even Medians binary search constructive algorithms interactive Statement F Codeforces Round 987 (Div. 2) {2031} PROGRAMMING 3000.0 Codeforces Round 987 (Div. 2) Editorial
6175 Genokraken binary search constructive algorithms data structures graphs interactive trees two pointers Statement D Codeforces Round 983 (Div. 2) {2032} PROGRAMMING 1750.0 Codeforces Round 983 (Div. 2) Editorial
1660 Library of Magic binary search bitmasks constructive algorithms interactive Statement G Codeforces Round 984 (Div. 3) {2036} PROGRAMMING Codeforces Round 984 (Div. 3) Editorial
1582 Broken Queries binary search bitmasks interactive Statement E Codeforces Round 994 (Div. 2) {2049} PROGRAMMING 2250.0 Codeforces Round #994 (Div. 2) Editorial
604 Baudelaire (hard version) binary search dfs and similar divide and conquer implementation interactive trees Statement G2 Codeforces Round 1020 (Div. 3) {2106} PROGRAMMING Codeforces Round 1020 (Div. 3) Editorial
1606 Baudelaire (easy version) binary search interactive trees Statement G1 Codeforces Round 1020 (Div. 3) {2106} PROGRAMMING Codeforces Round 1020 (Div. 3) Editorial
2414 Needle in a Numstack binary search brute force interactive math Statement D Codeforces Round 1022 (Div. 2) {2108} PROGRAMMING 2250.0 Codeforces Round 1022 Editorial
104 Inter Active (Hard Version) binary search bitmasks constructive algorithms graphs implementation interactive math probabilities Statement G2 Atto Round 1 (Codeforces Round 1041, Div. 1 + Div. 2) {2127} PROGRAMMING 2750.0 Atto Round 1 (Codeforces Round 1041, Div. 1 + Div. 2) Editorial
99 Inter Active (Easy Version) binary search constructive algorithms interactive interactive Statement G1 Atto Round 1 (Codeforces Round 1041, Div. 1 + Div. 2) {2127} PROGRAMMING 2750.0 Atto Round 1 (Codeforces Round 1041, Div. 1 + Div. 2) Editorial
1655 Interactive RBS (Hard Version) binary search bitmasks constructive algorithms dp interactive Statement C3 Codeforces Round 1040 (Div. 1) {2129} PROGRAMMING 750.0 Codeforces Round 1040 (Div. 1, Div. 2) Editorial
3835 Interactive RBS (Easy Version) binary search bitmasks constructive algorithms interactive Statement C1 Codeforces Round 1040 (Div. 1) {2129} PROGRAMMING 750.0 Codeforces Round 1040 (Div. 1, Div. 2) Editorial
2485 Interactive RBS (Medium Version) binary search bitmasks constructive algorithms interactive Statement C2 Codeforces Round 1040 (Div. 1) {2129} PROGRAMMING 750.0 Codeforces Round 1040 (Div. 1, Div. 2) Editorial
986 From the Unknown (Hard Version) binary search brute force constructive algorithms interactive math Statement D2 Codeforces Round 1046 (Div. 1) {2135} PROGRAMMING 1250.0 Codeforces Round 1046 (Div. 1, Div. 2) Editorial
134 Grand Finale: Snakes binary search interactive Statement F Codeforces Round 1058 (Div. 1) {2159} PROGRAMMING 3500.0 Codeforces Round 1058 Editorial
12250 Beautiful Permutation binary search interactive Statement D Codeforces Round 1059 (Div. 3) {2162} PROGRAMMING Codeforces Round 1059 (Div. 3) Editorial
2712 Diadrash (Easy Version) binary search divide and conquer interactive Statement D1 Codeforces Round 1063 (Div. 2) {2163} PROGRAMMING 1500.0 Codeforces Round 1063 Editorial
1484 Diadrash (Hard Version) binary search interactive Statement D2 Codeforces Round 1063 (Div. 2) {2163} PROGRAMMING 1250.0 Codeforces Round 1063 Editorial
1541 Locate binary search constructive algorithms greedy interactive Statement B Testing Round 20 (Unrated, Communication Problems) {2168} PROGRAMMING Testing Round 20 Editorial (officially unofficial)
3665 Flatten or Concatenate binary search divide and conquer interactive Statement E Good Bye 2025 {2178} PROGRAMMING 2250.0
140 Cacti Classification binary search interactive math Statement C 2025-2026 ICPC, NERC, Northern Eurasia Finals (Unrated, Online Mirror, ICPC Rules, Teams Preferred) {2181} PROGRAMMING Tutorial
1280 Comparable Permutations binary search greedy interactive sortings two pointers Statement C Codeforces Round 1073 (Div. 1) {2190} PROGRAMMING 1750.0 Codeforces Round 1073 (Div. 1, Div. 2) Editorial
49 Bowser's Castle (Easy Version) binary search constructive algorithms divide and conquer greedy interactive trees Statement H1 Codeforces Round 1085 (Div. 1 + Div. 2) {2207} PROGRAMMING 3250.0 Codeforces Round 1085 (Div. 1 + Div. 2) Editorial
2563 Unique Values (Hard version) binary search constructive algorithms divide and conquer interactive math Statement B2 Codeforces Round 1093 (Div. 1) {2219} PROGRAMMING 500.0
2912 Unique Values (Easy version) binary search divide and conquer interactive Statement B1 Codeforces Round 1093 (Div. 1) {2219} PROGRAMMING 750.0