Home
Problems
Submissions
Users
Contests
About
>
Status
Tips
API
Github
Log in
or
Sign up
This site works best with JavaScript enabled.
Problems
«
1
2
3
4
5
»
Problem search
Full text search
Has editorial
Show problem types
Category
All
---
AAC
ACC
APIO
Balkan OI
Baltic OI
BlueBook
Brazil OI
Bubble Cup
Bulgarian OI
CCC
CCO
CEOI
China NOI
Classics
COCI
CSPC
CTF
Data Structure Tests
DMOPC
DWITE
ECOO
EGOI
ESOI
FHC
Fun Math
GFSSOC
Google Code Jam
Google Hash Code
Google Kick Start
ICPC
IOI
JOI
Mock CCC
Mock CCO
MWC
Olympiads School
POI
SAC Coding Challenge
Seasonal
SIUCF
Taiwan NOI
TLE
TSOC
Uncategorized
VM7WC
WAC
Waterloo Local
Woburn Challenge
YAC
Point range
Go
Random
Hot problems
DWITE '10 R3 #3 - Dominos Tiling
WC '01 P3 - Back to the Future
DMOPC '17 Contest 4 P1 - Ribbon Colouring Fun
APIO '10 P1 - Commando
Counting Subsequences
GFSSOC '15 Winter S1 - OR-deal
CCC '13 S1 - From 1987 to 2013
Problem
Category
Points
AC % ▴
Users
CCO '22 P2 - Rainy Markets
CCO
17p
18.1%
106
CCO '08 P5 - Candy
CCO
7p
18.2%
237
Mock CCO '18 Contest 2 Problem 6 - Victor's Cubes
Mock CCO
20p
18.3%
9
CCOQR '16 - Through A Maze Darkly
CCC
20p
18.4%
104
CCO '15 P6 - Eggscavation
CCO
30p
18.5%
70
CCO '13 P1 - All Your Base Belong to Palindromes
CCO
10p
18.6%
209
CCO '15 P4 - Cars on Ice
CCO
10p
18.8%
208
CCO '21 P4 - Travelling Merchant
CCO
25p
19.0%
54
CCO '11 P2 - Vampire Tunnels
CCO
15p
19.0%
320
CCO '16 P5 - Zombie Apocalypse
CCO
15p
19.1%
141
CCO '97 P6 - Aligning DNA
CCO
7
19.1%
11
CCO '18 P5 - Boring Lectures
CCO
20p
19.2%
127
CCO '13 P5 - Transforming Comets
CCO
15p
19.3%
74
CCO '22 P4 - Bi-ing Lottery Treekets
CCO
20p
19.4%
31
CCO '20 P4 - Travelling Salesperson
CCO
25p
19.4%
92
CCO '22 P6 - Good Game
CCO
35p
19.6%
12
CCO '16 P6 - Pirates
CCO
25p
20.1%
71
CCO '20 P1 - A Game with Grundy
CCO
10p
20.2%
215
CCO '08 P6 - Landing
CCO
45
20.2%
40
CCO '21 P3 - Through Another Maze Darkly
CCO
25p
20.5%
49
CCO '04 P2 - Hockey Scores
CCO
12
20.5%
66
CCO '06 P2 - R & J
CCO
10
20.8%
35
CCO '99 P4 - Maple Roundup
CCO
10
21.1%
28
CCO '02 P2 - Game Show Math
CCO
12
21.4%
35
CCO '15 P1 - Hungry Fox
CCO
15p
21.6%
221
CCO '16 P1 - Field Trip
CCO
10p
21.8%
171
Mock CCO '18 Contest 2 Problem 4 - Victor's Rectangles
Mock CCO
20p
21.9%
22
CCOQR '16 - Data Structure
CCC
15p
22.1%
177
CCO Preparation Test 4 P3 - Dynamic MST
Mock CCO
25p
22.1%
49
CCO '00 P5 - Millikan's Oil Droplet Experiment
CCO
7
22.3%
54
CCO '21 P5 - Bread First Search
CCO
20p
22.7%
65
CCO '12 P1 - Choose Your Own Arithmetic
CCO
7
22.8%
224
CCO '23 P1 - Binaria
CCO
12p
22.8%
173
CCO '11 P3 - Spies Like Us
CCO
10p
22.8%
203
CCO Preparation Test 6 P3 - HopScotch
Mock CCO
20p
23.1%
140
CCO '14 P5 - Early Exam Evacuation
CCO
20p
23.3%
87
CCO '13 P3 - LHC
CCO
12p
23.3%
404
CCO '19 P2 - Sirtet
CCO
20p
23.5%
85
CCO '13 P4 - A Romantic Movie Outing
CCO
20p
23.6%
92
Mock CCO '18 Contest 4 Problem 3 - Counterattack
Mock CCO
15p
23.6%
285
CCO '98 P5 - Text Segmentation
CCO
10
23.7%
18
CCO '10 P3 - Wowow
CCO
15p
23.9%
282
CCO '12 P5 - Sample Size
CCO
7
24.0%
171
Mock CCO '17 Problem 6 - Dire Consequences
Mock CCO
20
24.2%
25
CCO '05 P1 - Number Matrix
CCO
10
24.2%
161
CCO Preparation Test 6 P1 - Bus Routes
Mock CCO
20p
24.2%
6
CCO '12 P2 - The Hungary Games
CCO
15
24.3%
481
Mock CCO '18 Contest 1 Problem 5 - A Counting Problem
Mock CCO
20p
24.5%
9
Mock CCO '18 Contest 4 Problem 5 - Spawn More Overlords
Mock CCO
20p
24.8%
35
CCO '98 P4 - Scoring Curling
CCO
7p
25.0%
8
«
1
2
3
4
5
»