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
»
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
APIO '10 P1 - Commando
Counting Subsequences
A Math Contest P5 - Good Arrays
ECOO '13 R1 P1 - Take a Number
CCC '24 J3 - Bronze Count
CCC '24 J5 - Harvest Waterloo
Problem
Category
Points
AC % ▾
Users
IOI '07 P5 - Pairs
IOI
25p
10.1%
117
IOI '16 P4 - Paint by Numbers (Standard I/O)
IOI
15p
10.0%
63
IOI '08 P3 - Fish
IOI
35p
9.9%
63
IOI '19 P6 - Sky Walking
IOI
40p
9.6%
12
IOI '13 P3 - Wombats (Standard I/O)
IOI
40p
9.5%
60
IOI '13 P6 - Game
IOI
25p
9.3%
80
IOI '16 P3 - Shortcut
IOI
40p
9.0%
15
IOI '98 P1 - Contact
IOI
10p
8.9%
58
IOI '15 P3 - Teams
IOI
35p
8.8%
34
IOI '14 P4 - Gondola (Standard I/O)
IOI
15
8.5%
222
IOI '13 P6 - Game (Standard I/O)
IOI
17p
8.4%
150
IOI '15 P1 - Boxes with Souvenirs (Standard I/O)
IOI
15p
8.2%
189
IOI '19 P5 - Vision Program
IOI
20p
8.2%
33
IOI '22 P2 - Prisoner Challenge
IOI
25p
8.2%
25
IOI '04 P2 - Hermes (Hard)
IOI
20p
8.1%
9
IOI '22 P1 - Catfish Farm
IOI
25p
8.1%
44
IOI '21 P5 - Dungeons Game
IOI
30p
8.1%
9
IOI '15 P4 - Horses (Standard I/O)
IOI
15p
7.6%
162
IOI '22 P3 - Radio Towers
IOI
30p
7.2%
15
IOI '16 P6 - Aliens
IOI
30p
7.1%
81
IOI '19 P3 - Rectangles
IOI
30p
6.9%
25
IOI '04 P1 - Artemis
IOI
15p
6.9%
68
IOI '15 P2 - Scales
IOI
25p
6.7%
24
IOI '00 P6 - Building with Blocks
IOI
20p
6.6%
7
IOI '20 P1 - Comparing Plants
IOI
40p
6.4%
17
IOI '23 P5 - Overtaking
IOI
25p
6.1%
11
IOI '16 P6 - Aliens (Standard I/O)
IOI
30p
6.1%
63
IOI '22 P5 - Rarest Insects
IOI
30p
5.3%
22
IOI '19 P2 - Split the Attractions
IOI
40p
5.1%
26
IOI '23 P4 - Beech Tree
IOI
35p
4.9%
3
IOI '21 P3 - Fountain Parks
IOI
30p
4.8%
7
IOI '23 P3 - Soccer Stadium
IOI
30p
4.7%
12
IOI '23 P1 - Closing Time
IOI
25p
4.5%
20
IOI '11 P6 - Parrots
IOI
20p
3.6%
16
IOI '23 P6 - Robot Contest
IOI
40p
3.4%
2
IOI '15 P3 - Teams (Standard I/O)
IOI
35p
3.4%
37
IOI '04 P3 - Polygon
IOI
20p
3.1%
1
IOI '22 P6 - Thousands Islands
IOI
30p
3.1%
6
IOI '23 P2 - Longest Trip
IOI
25p
3.1%
13
IOI '12 P1 - Pebbling Odometer
IOI
30p
2.9%
4
IOI '13 P2 - Art Class (Standard I/O)
IOI
20p
2.7%
90
IOI '20 P5 - Counting Mushrooms
IOI
35p
2.5%
3
IOI '19 P4 - Broken Line
IOI
35p
2.3%
4
IOI '16 P3 - Shortcut (Standard I/O)
IOI
40p
1.8%
7
IOI '10 P2 - Hotter Colder
IOI
20
0.5%
3
IOI '17 P1 - Nowruz
IOI
20p
0.0%
0
IOI '10 P7 - Maze
IOI
25p
0.0%
0
«
1
2
3
4
»