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4450 Palindrome Degree hashing strings Statement D Codeforces Beta Round 7 {7} PROGRAMMING 2200
3141 Test hashing strings Statement E Codeforces Beta Round 25 (Div. 2 Only) {25} PROGRAMMING Codeforces Beta Round #25 Solution Analysis 2300
916 Tricky and Clever Password binary search constructive algorithms data structures greedy hashing strings Statement E Codeforces Beta Round 30 (Codeforces format) {30} PROGRAMMING Codeforces Beta Round #30. Tutorial for problem A 2700
3561 Spelling Check hashing implementation strings Statement J School Team Contest 1 (Winter Computer School 2010/11) {39} PROGRAMMING School Team Contest #1 (Winter Computer School 2010/11): Problem K Tutorial 1600
2087 Beaver data structures dp greedy hashing strings two pointers Statement C Codeforces Beta Round 71 {79} PROGRAMMING Codeforces Beta Round #71 Editorial 1800
3237 Petr# brute force data structures hashing strings Statement B Codeforces Beta Round 86 (Div. 1 Only) {113} PROGRAMMING Codeforces Beta Round #86 Editorial 1900
620 String Transformation hashing strings Statement D Codeforces Beta Round 90 {119} PROGRAMMING Codeforces Beta Round #90 (editorial) 2500
24623 Password binary search dp hashing string suffix structures strings Statement B Codeforces Beta Round 93 (Div. 1 Only) {126} PROGRAMMING Tutorial 1800
2860 String brute force constructive algorithms hashing implementation string suffix structures strings Statement B Codeforces Beta Round 94 (Div. 1 Only) {128} PROGRAMMING 3219 2200
9228 Common Divisors brute force hashing implementation math strings Statement D Codeforces Round 117 (Div. 2) {182} PROGRAMMING Codeforces Round #117 (Div. 2) Разбор Задач 1400
599 The Next Good String data structures greedy hashing strings Statement D Codeforces Round 124 (Div. 1) {196} PROGRAMMING Codeforces Round #124 — editorial 2600
366 Polycarpus is Looking for Good Substrings bitmasks hashing implementation Statement B VK Cup 2012 Finals (unofficial online-version) {212} PROGRAMMING 2300
942 Two Permutations data structures hashing strings Statement E Codeforces Round 131 (Div. 1) {213} PROGRAMMING Codeforces Round #131 Tutorial 2600
8996 Queries for Number of Palindromes dp hashing strings Statement H CROC-MBTU 2012, Elimination Round (ACM-ICPC) {245} PROGRAMMING КРОК-МВТУ 2012, Отборочный раунд (Разбор) 1900
1564 Tree-String Problem *special dfs and similar hashing strings Statement E Croc Champ 2013 - Qualification Round {291} PROGRAMMING 2400
1083 Good Substrings hashing strings Statement G1 ABBYY Cup 3.0 {316} PROGRAMMING 1700
776 Have You Ever Heard About the Word? greedy hashing string suffix structures strings Statement D Codeforces Round 189 (Div. 1) {319} PROGRAMMING Codeforces Round #189 — Editorial 2700
488 Xenia and String Problem dp hashing implementation string suffix structures strings Statement E Codeforces Round 207 (Div. 1) {356} PROGRAMMING 9210 2800
860 DZY Loves Strings binary search hashing strings two pointers Statement D Codeforces Round 254 (Div. 1) {444} PROGRAMMING Codeforces Round #254 Editorial 2400
2023 Fedor and Essay dfs and similar dp graphs hashing strings Statement D Codeforces Round 267 (Div. 2) {467} PROGRAMMING 2100
1059 Misha and LCP on Tree binary search dfs and similar hashing string suffix structures trees Statement E Codeforces Round 285 (Div. 1) {504} PROGRAMMING 15743 3000
8082 Watto and Mechanism binary search data structures hashing string suffix structures strings Statement C Codeforces Round 291 (Div. 2) {514} PROGRAMMING Codeforces Round #291 (Div. 2) Editorial 1900
593 And Yet Another Bracket Sequence data structures greedy hashing string suffix structures strings Statement F VK Cup 2015 - Round 1 {524} PROGRAMMING VK Cup Round 1 (+ online mirror) editorial 2700
16351 Vitaliy and Pie greedy hashing strings Statement A Codeforces Round 297 (Div. 2) {525} PROGRAMMING Codeforces Round #297 (Div.2) Editorial 1200
2431 Om Nom and Necklace hashing string suffix structures strings Statement D ZeptoLab Code Rush 2015 {526} PROGRAMMING ZeptoLab Code Rush 2015 — Editorial 2200
2428 Correcting Mistakes constructive algorithms dp greedy hashing strings two pointers Statement E VK Cup 2015 - Round 2 (unofficial online mirror, Div. 1 only) {533} PROGRAMMING Разбор VK Cup Round 2 1800
953 Encoding hashing string suffix structures strings Statement F VK Cup 2015 - Round 2 (unofficial online mirror, Div. 1 only) {533} PROGRAMMING Разбор VK Cup Round 2 2400
4593 Tavas and Malekas greedy hashing string suffix structures strings Statement D Codeforces Round 299 (Div. 2) {535} PROGRAMMING Codeforces Round #299 Editorial 2100
11640 Equivalent Strings divide and conquer hashing sortings strings Statement B Codeforces Round 313 (Div. 1) {559} PROGRAMMING Codeforces Round 313 — Extended editoral 1800
2557 Kefa and Watch data structures hashing strings Statement E Codeforces Round 321 (Div. 2) {580} PROGRAMMING Codeforces Round #321 Editorial 2700
1243 Acyclic Organic Compounds data structures dfs and similar dsu hashing strings trees Statement D Codeforces Round 333 (Div. 1) {601} PROGRAMMING Codeforces Round #333 — editorial 2400
841 Marbles hashing strings Statement C Codeforces Round 336 (Div. 1) {607} PROGRAMMING Codeforces Round #336 Editorial 2600
2741 New Year and Ancient Prophecy dp hashing strings Statement D Good Bye 2015 {611} PROGRAMMING Tutorial 1900
525 Puzzle Lover dp hashing strings Statement E Codeforces Round 339 (Div. 1) {613} PROGRAMMING Tutorial 3200
2368 Messenger data structures hashing implementation string suffix structures strings Statement D Codeforces Round 344 (Div. 2) {631} PROGRAMMING Editorial Codeforces Round #344 (Div. 2) 2100
3349 Spy Syndrome 2 data structures dp hashing implementation sortings string suffix structures strings Statement C Manthan, Codefest 16 {633} PROGRAMMING Manthan, Codefest 16: Editorials 1900
2481 String Set Queries brute force data structures hashing string suffix structures strings Statement F Educational Codeforces Round 16 {710} PROGRAMMING Editorial of Educational Codeforces Round 16 2700
1535 Games on a CD data structures hashing string suffix structures strings Statement E Technocup 2017 - Elimination Round 1 (Unofficially Open for Everyone, Rated for Div. 2) {727} PROGRAMMING Tutorial 2300
2461 Felicity is Coming! data structures hashing sortings strings Statement C Codecraft-17 and Codeforces Round 391 (Div. 1 + Div. 2, combined) {757} PROGRAMMING CodeCraft-17 and Codeforces Round #391 (Div. 1 + Div. 2, combined) Editorial 1900
2984 Two strings binary search hashing strings two pointers Statement C Educational Codeforces Round 17 {762} PROGRAMMING Tutorial 2100
980 Peterson Polyglot brute force dfs and similar dsu hashing strings trees Statement C Codeforces Round 402 (Div. 1) {778} PROGRAMMING Codeforces Round #402, Editorial 2600
168 Rap God data structures dfs and similar hashing strings trees Statement D Codeforces Round 406 (Div. 1) {786} PROGRAMMING Codeforces Round #406 Editorial 3300
1059 Liar binary search dp hashing string suffix structures Statement E Codeforces Round 422 (Div. 2) {822} PROGRAMMING Codeforces Round #422 (Div. 2) Editorial 2500
1941 String Compression dp hashing string suffix structures strings Statement F Educational Codeforces Round 25 {825} PROGRAMMING Educational Codeforces Round 25 - Editorial 2400
4648 Palindromic characteristics brute force dp hashing strings Statement D Codeforces Round 427 (Div. 2) {835} PROGRAMMING Editorial 1900
1575 Swapping Characters brute force hashing implementation strings Statement E Educational Codeforces Round 34 (Rated for Div. 2) {903} PROGRAMMING Educational Codeforces Round 34 Editorial 2200
1056 Death Stars (medium) hashing strings Statement A2 Helvetic Coding Contest 2018 online mirror (teams allowed, unrated) {958} PROGRAMMING helvetic-coding-contest-2018-editorial.pdf 2100
944 k-substrings binary search hashing string suffix structures Statement F Educational Codeforces Round 41 (Rated for Div. 2) {961} PROGRAMMING Educational Codeforces Round 41 Editorial 2700
2706 Frequency of String hashing string suffix structures strings Statement D 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) 2400
2148 Isomorphic Strings hashing strings Statement F Educational Codeforces Round 44 (Rated for Div. 2) {985} PROGRAMMING Educational Codeforces Round 44 Editorial 2400
1600 Abbreviation dp hashing strings Statement F Codeforces Round 494 (Div. 3) {1003} PROGRAMMING 60417 2400
1077 The Supersonic Rocket geometry hashing strings Statement E Codeforces Round 502 (in memory of Leopoldo Taravilse, Div. 1 + Div. 2) {1017} PROGRAMMING Разбор (англ.) 2400
320 Speckled Band data structures divide and conquer hashing string suffix structures strings Statement G Codeforces Round 519 by Botan Investments {1043} PROGRAMMING Codeforces Round #519 Editorial 3500
5449 Palindrome Pairs hashing strings Statement I Bubble Cup 11 - Finals [Online Mirror, Div. 1] {1045} PROGRAMMING E 1700
1205 Vasya and Big Integers binary search data structures dp hashing strings Statement E Educational Codeforces Round 51 (Rated for Div. 2) {1051} PROGRAMMING Educational Codeforces Round 51 Editorial 2500
2791 Check Transcription brute force data structures hashing strings Statement E Mail.Ru Cup 2018 Round 3 {1056} PROGRAMMING Mail.Ru Cup 2018 Round 3 Editorial 2100
130 Palindromic Magic data structures hashing strings Statement H Avito Cool Challenge 2018 {1081} PROGRAMMING 63888 3500
4536 Sasha and One More Name constructive algorithms hashing strings Statement B Codeforces Round 539 (Div. 1) {1109} PROGRAMMING Codeforces Round #539 Editorial 1800
1000 Morse Code binary search data structures dp hashing sortings string suffix structures strings Statement C Codeforces Round 542 [Alex Lopashev Thanks-Round] (Div. 1) {1129} PROGRAMMING 65520 2300
6993 Camp Schedule greedy hashing strings Statement B Codeforces Round 545 (Div. 1) {1137} PROGRAMMING Codeforces Round #545 – Editorial 1700
9290 Compress Words brute force hashing implementation string suffix structures strings Statement E Codeforces Round 578 (Div. 2) {1200} PROGRAMMING Codeforces Round #578 (Div. 2) Editorial 2000
1216 Indie Album data structures dfs and similar hashing string suffix structures strings trees Statement G Educational Codeforces Round 71 (Rated for Div. 2) {1207} PROGRAMMING Educational Codeforces Round 71 Editorial 2600
744 Madhouse (Hard version) brute force constructive algorithms hashing interactive math Statement C2 Codeforces Round 612 (Div. 1) {1286} PROGRAMMING Codeforces Round #612 - Editorial 2900
719 Concatenation with intersection data structures hashing strings two pointers Statement E Codeforces Round 622 (Div. 2) {1313} PROGRAMMING 2500.0 Editorial 2800
1685 Reachable Strings data structures hashing string suffix structures strings strings Statement D Codeforces Round 625 (Div. 1, based on Technocup 2020 Final Round) {1320} PROGRAMMING 2000.0 Codeforces Round #625 Editorial
13262 Prefix-Suffix Palindrome (Easy version) hashing string suffix structures strings Statement D1 Codeforces Global Round 7 {1326} PROGRAMMING 1000.0 74961 1500
11700 Prefix-Suffix Palindrome (Hard version) greedy hashing string suffix structures strings Statement D2 Codeforces Global Round 7 {1326} PROGRAMMING 1000.0 74961 1800
13499 Spy-string bitmasks brute force constructive algorithms dp hashing strings Statement F Codeforces Round 644 (Div. 3) {1360} PROGRAMMING Codeforces Round #644 (Div. 3) Editorial 1700
446 Twilight and Ancient Scroll (easier version) dp hashing implementation string suffix structures strings Statement E1 Codeforces Round 662 (Div. 2) {1393} PROGRAMMING 1500.0 Codeforces Round #662 Editorial
1247 Death DBMS data structures hashing string suffix structures strings trees Statement G Educational Codeforces Round 97 (Rated for Div. 2) {1437} PROGRAMMING 84149
17267 String Equality dp greedy hashing implementation strings Statement C Codeforces Round 685 (Div. 2) {1451} PROGRAMMING 1250.0 Editorial — Codeforces Round #685
1005 Song of the Sirens divide and conquer hashing math strings Statement G Good Bye 2020 {1466} PROGRAMMING 2500.0 Good Bye 2020 Editorial
2197 A Bit Similar bitmasks brute force hashing string suffix structures strings two pointers Statement E Educational Codeforces Round 101 (Rated for Div. 2) {1469} PROGRAMMING Educational Codeforces Round 101 Editorial
35370 Double-ended Strings brute force dp hashing strings Statement C Codeforces Round 710 (Div. 3) {1506} PROGRAMMING Editorial
605 String Distance binary search data structures hashing string suffix structures strings Statement F Educational Codeforces Round 110 (Rated for Div. 2) {1535} PROGRAMMING 91481
16030 Diluc and Kaeya dp hashing number theory Statement C Codeforces Round 724 (Div. 2) {1536} PROGRAMMING 1500.0 Codeforces Round #724 — Editorial 1500
16236 Erase and Extend (Easy Version) binary search brute force dp greedy hashing string suffix structures strings Statement E1 Codeforces Round 726 (Div. 2) {1537} PROGRAMMING 1250.0 Codeforces Round #726 (Div.2) Editorial
6133 Erase and Extend (Hard Version) binary search data structures greedy hashing string suffix structures strings Statement E2 Codeforces Round 726 (Div. 2) {1537} PROGRAMMING 1750.0 Codeforces Round #726 (Div.2) Editorial
3211 Funny Substrings brute force data structures hashing implementation strings Statement E Codeforces Round 725 (Div. 3) {1538} PROGRAMMING Codeforces Round #725 (Div. 3) Editorial
15457 Reverse String brute force dp hashing strings Statement B Harbour.Space Scholarship Contest 2021-2022 (open for everyone, rated, Div. 1 + Div. 2) {1553} PROGRAMMING 500.0 Harbour.Space Scholarship Contest 2021-2022 (Div. 1 + Div. 2) Editorial
403 The Sum of Good Numbers hashing probabilities Statement G Educational Codeforces Round 115 (Rated for Div. 2) {1598} PROGRAMMING 95890
243 Alphabetic Tree binary search data structures dfs and similar hashing string suffix structures strings trees Statement G Codeforces Round 758 (Div.1 + Div. 2) {1608} PROGRAMMING 2750.0 Editorial of Codeforces Round #758 (Div.1 + Div. 2)
4585 Masha-forgetful brute force constructive algorithms dp hashing implementation strings Statement E Codeforces Round 764 (Div. 3) {1624} PROGRAMMING Codeforces Round #764 (Div. 3) Editorial
1479 Minimal String Xoration bitmasks data structures divide and conquer hashing strings Statement F Codeforces Round 778 (Div. 1 + Div. 2, based on Technocup 2022 Final Round) {1654} PROGRAMMING 3000.0 Editorial of Codeforces Round #778 (Div. 1 + Div. 2, based on Technocup 2022 Final Round) 2800
3162 Preorder combinatorics divide and conquer dp dsu hashing trees Statement E Educational Codeforces Round 127 (Rated for Div. 2) {1671} PROGRAMMING 102181
2545 Prefix Function Queries bitmasks brute force data structures hashing string suffix structures strings trees Statement E Educational Codeforces Round 134 (Rated for Div. 2) {1721} PROGRAMMING 106416
2498 Cut Substrings combinatorics dp hashing strings two pointers Statement G Codeforces Round 820 (Div. 3) {1729} PROGRAMMING Codeforces Round #820 (Div. 3) Editorial
8350 Problem with Random Tests brute force hashing probabilities Statement D Educational Codeforces Round 137 (Rated for Div. 2) {1743} PROGRAMMING Educational Codeforces Round 137 Editorial 1700
1519 Hossam and Range Minimum Query binary search bitmasks data structures hashing probabilities strings trees Statement F Codeforces Round 837 (Div. 2) {1771} PROGRAMMING 3500.0 Codeforces Round #837 (Div. 2) Editorial
29230 Remove Two Letters data structures greedy hashing strings Statement D Codeforces Round 855 (Div. 3) {1800} PROGRAMMING Codeforces Round 855 (Div. 3) Editorial
2521 Symmetree dfs and similar hashing trees Statement G Codeforces Round 855 (Div. 3) {1800} PROGRAMMING Codeforces Round 855 (Div. 3) Editorial
1645 Palindrome Partition binary search brute force data structures dp hashing strings Statement C Codeforces Round 873 (Div. 1) {1827} PROGRAMMING 1500.0 Codeforces Round #873 (Div. 1 & 2) Editorial 2600
2168 Hyperregular Bracket Strings combinatorics hashing number theory sortings two pointers Statement C Codeforces Round 875 (Div. 1) {1830} PROGRAMMING 1750.0 Codeforces Round #875 (Div.1 + Div. 2) Editorial
12494 Binary String Copying binary search brute force data structures hashing strings Statement C Educational Codeforces Round 152 (Rated for Div. 2) {1849} PROGRAMMING 118752
12991 Torn Lucky Ticket brute force dp hashing implementation math Statement C Educational Codeforces Round 157 (Rated for Div. 2) {1895} PROGRAMMING Educational Codeforces Round 157 Editorial
5567 Collapsing Strings binary search data structures dfs and similar hashing strings trees Statement E Educational Codeforces Round 159 (Rated for Div. 2) {1902} PROGRAMMING Educational Codeforces Round 159 Editorial
649 Pumping Lemma hashing string suffix structures strings Statement G Pinely Round 3 (Div. 1 + Div. 2) {1909} PROGRAMMING 4000.0 Editorial of Pinely Round 3 (Div. 1 + Div. 2)
536 Palindromic Problem binary search data structures hashing strings Statement F Educational Codeforces Round 160 (Rated for Div. 2) {1913} PROGRAMMING 123493
4528 Non-Palindromic Substring data structures hashing implementation math strings Statement B Codeforces Round 934 (Div. 1) {1943} PROGRAMMING 1250.0 Codeforces Round #934 (Div1, Div2) Editorial
4466 No Palindromes brute force constructive algorithms greedy hashing implementation strings Statement E Codeforces Global Round 25 {1951} PROGRAMMING 2250.0 Codeforces Global Round 25 Editorial
5268 Division + LCP (easy version) binary search data structures dp hashing string suffix structures strings Statement G1 Codeforces Round 943 (Div. 3) {1968} PROGRAMMING 129096 1900
2494 Division + LCP (hard version) binary search brute force data structures dp hashing math string suffix structures strings Statement G2 Codeforces Round 943 (Div. 3) {1968} PROGRAMMING 129096 2200
7833 Fixing a Binary String bitmasks brute force constructive algorithms greedy hashing strings Statement D Codeforces Round 951 (Div. 2) {1979} PROGRAMMING 2000.0 Codeforces Round 951 (Div. 2) Editorial
12961 Permutation of Rows and Columns constructive algorithms data structures hashing math matrices sortings Statement E Codeforces Round 950 (Div. 3) {1980} PROGRAMMING 130135
3869 ''a'' String Problem hashing implementation math string suffix structures strings Statement D Codeforces Global Round 26 {1984} PROGRAMMING 2500.0 Codeforces Global Round 26 Editorial
23267 Substring and Subsequence bitmasks brute force dp graphs greedy hashing strings trees Statement B Educational Codeforces Round 167 (Rated for Div. 2) {1989} PROGRAMMING Educational Codeforces Round 167 Editorial
4562 Message Transmission Error (hard version) hashing strings two pointers Statement C2 Testing Round 19 (Div. 3) {2010} PROGRAMMING 1700
1369 C+K+S brute force constructive algorithms dfs and similar graphs greedy hashing math strings Statement C Codeforces Round 980 (Div. 1) {2023} PROGRAMMING 1500.0 135341
2015 Permutations Harmony brute force combinatorics constructive algorithms greedy hashing implementation math Statement E Rayan Programming Contest 2024 - Selection (Codeforces Round 989, Div. 1 + Div. 2) {2034} PROGRAMMING 2000.0 Rayan 2024 Selection Round Editorial
746 Polyathlon data structures hashing string suffix structures strings Statement I 2024-2025 ICPC, NERC, Southern and Volga Russian Regional Contest (Unrated, Online Mirror, ICPC Rules, Preferably Teams) {2038} PROGRAMMING 2500
224 Naive String Splits brute force greedy hashing strings Statement G Good Bye 2024: 2025 is NEAR {2053} PROGRAMMING 4250.0 Good Bye 2024: 2025 is NEAR Editorial
89 Cosmic Divide brute force geometry hashing math strings Statement F Codeforces Round 996 (Div. 2) {2055} PROGRAMMING 3500.0 Codeforces Round 996 (Div. 2) Editorial
7000 Palindrome Shuffle binary search greedy hashing strings two pointers Statement D Educational Codeforces Round 174 (Rated for Div. 2) {2069} PROGRAMMING 139774
280 Shifts and Swaps graphs hashing strings Statement F Codeforces Round 1030 (Div. 2) {2118} PROGRAMMING 3500.0 Codeforces Round 1030 (Div. 2) Editorial
511 Famous Choreographer hashing strings Statement G Codeforces Round 1043 (Div. 3) {2132} PROGRAMMING Codeforces Round 1043 (Div. 3) Editorial