Problems

Problem search

Point range
Go Random

Hot problems

Problem Category Points AC % Users
Baltic OI '13 P1 - Ball Machine Baltic OI 15p 28.2% 20
Baltic OI '13 P2 - Palindrome-Free Numbers Baltic OI 15p 25.2% 97
Baltic OI '13 P4 - Brunhilda's Birthday Baltic OI 15p 30.0% 12
Baltic OI '13 P5 - Tracks in the Snow Baltic OI 12p 29.6% 91
Baltic OI '14 P5 - Portals Baltic OI 15p 25.3% 19
Baltic OI '14 P6 - Senior Postmen Baltic OI 15p 18.9% 15
Baltic OI '15 P3 - Network Baltic OI 15p 25.6% 34
Baltic OI '15 P5 - Hacker Baltic OI 15p 50.0% 19
Baltic OI '16 P4 - Cities Baltic OI 15p 29.6% 32
Baltic OI '16 P6 - Swap Baltic OI 15p 22.5% 6
Baltic OI '17 P5 - Plus Minus Baltic OI 15p 39.1% 28
Baltic OI '17 P6 - Cat in a tree Baltic OI 15p 35.9% 117
Baltic OI '18 P6 - Paths Baltic OI 15p 32.9% 105
Baltic OI '19 P2 - Nautilus Baltic OI 15p 33.4% 78
Baltic OI '19 P4 - Tom's Kitchen Baltic OI 15p 23.6% 79
Back To School '16: Cherry Tree Seasonal 12p 41.8% 321
Back To School '17: New English Seasonal 12p 10.1% 82
Back To School '17: Sour Candy Seasonal 15p 28.5% 85
Back To School '18: The Golden Porcupine Seasonal 15p 33.0% 214
Back To School '19: Heist Night Seasonal 15p 14.7% 31
Back To School '19: Unstable Books Seasonal 15p 28.4% 33
Back to School '24 P3 - Tournament Uncategorized 12 35.3% 152
Back to School '24 P4 - Candidates Uncategorized 15p 16.6% 80
Back to School '24 P5 - Snitching Uncategorized 15p 12.1% 68
Calendar Contest Problem 5 — Reign of Terror Uncategorized 15 3.3% 2
Canada Day Contest 2021 - CCC Bad Haha Seasonal 12 35.5% 260
Canada Day Contest 2021 - Starfall Seasonal 15 32.4% 112
Casino Crisis Uncategorized 12p 33.9% 65
CCC '02 S3 - Blindfold CCC 15 6.3% 159
CCC '03 S4 - Substrings CCC 15p 7.8% 394
CCC '05 S5 - Pinball Ranking CCC 12p 19.4% 766
CCC '06 S3 - Tin Can Telephone CCC 12 20.6% 542
CCC '06 S5 - Origin of Life CCC 15 19.8% 127
CCC '09 S5 - Wireless CCC 12p 35.3% 647
CCC '10 S3 - Firehose CCC 15p 18.9% 702
CCC '10 S4 - Animal Farm CCC 15p 25.7% 542
CCC '11 S4 - Blood Distribution CCC 15p 8.1% 170
CCC '11 S5 - Switch CCC 12p 17.6% 425
CCC '12 S4 - A Coin Game CCC 15 27.0% 474
CCC '13 S5 - Factor Solitaire CCC 15p 42.1% 759
CCC '14 S4 - Tinted Glass Window CCC 15p 29.3% 696
CCC '15 S4 - Convex Hull CCC 15p 27.4% 1196
CCC '16 S3 - Phonomenal Reviews CCC 12p 26.0% 1166
CCC '16 S4 - Combining Riceballs CCC 15p 28.9% 1008
CCC '18 S3 - RoboThieves CCC 12p 14.2% 1171
CCC '18 S4 - Balanced Trees CCC 15p 17.0% 604
CCC '19 S3 - Arithmetic Square CCC 12p 13.7% 530
CCC '20 J4 - Cyclic Shifts (Hard) CCC 12p 3.8% 45
CCC '20 S2 - Escape Room (Hard) CCC 15p 5.4% 57
CCC '20 S3 - Searching for Strings CCC 12p 9.2% 962