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
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
WC '96 P6 - Bases Multiplication
Problem
Category
Points
AC % ▾
Users
IOI '14 P2 - Wall (Standard I/O)
IOI
20p
15.9%
286
IOI '05 P4 - Birthday
IOI
12p
15.7%
141
IOI '15 P6 - Towns
IOI
40p
15.5%
59
IOI '17 P2 - Wiring
IOI
25p
15.5%
56
IOI '12 P2 - Parachute Rings
IOI
25p
15.3%
24
IOI '11 P1 - Tropical Garden
IOI
25p
15.3%
38
IOI '07 P1 - Aliens
IOI
12p
15.3%
21
IOI '11 P2 - Race (Standard I/O)
IOI
17p
15.3%
537
IOI '18 P1 - Combo
IOI
15p
15.0%
179
IOI '13 P5 - Robots (Standard I/O)
IOI
20p
15.0%
278
IOI '02 P5 - Bus Terminals
IOI
30p
14.8%
53
IOI '09 P6 - Mecho
IOI
15
14.8%
324
IOI '20 P6 - Stations
IOI
20p
14.5%
22
IOI '99 P2 - Hidden Codes
IOI
20p
14.4%
10
IOI '16 P1 - Detecting Molecules (Standard I/O)
IOI
12p
14.1%
230
IOI '20 P2 - Connecting Supertrees
IOI
15p
13.8%
54
IOI '21 P6 - Bit Shift Registers
IOI
30p
13.8%
8
IOI '21 P1 - Distributing Candies
IOI
30p
13.4%
29
IOI '09 P1 - Archery
IOI
45p
13.4%
37
IOI '05 P3 - Mountain
IOI
20p
13.4%
299
IOI '20 P4 - Packing Biscuits
IOI
25p
13.4%
15
IOI '15 P1 - Boxes with Souvenirs
IOI
15p
13.4%
98
IOI '99 P6 - A Strip of Land
IOI
20p
13.4%
34
IOI '04 P5 - Farmer
IOI
15p
13.3%
210
IOI '13 P3 - Wombats
IOI
40p
13.2%
38
IOI '16 P2 - Roller Coaster Railroad (Standard I/O)
IOI
35p
12.9%
26
IOI '97 P1 - Mars Explorer
IOI
20p
12.8%
16
IOI '08 P6 - Pyramid Base
IOI
40p
12.5%
7
IOI '16 P4 - Paint by Numbers
IOI
15p
12.4%
54
IOI '14 P6 - Holiday (Standard I/O)
IOI
30p
12.3%
135
IOI '01 P6 - Depot
IOI
30p
12.1%
39
IOI '17 P5 - Simurgh
IOI
40p
12.1%
16
IOI '18 P6 - Meetings
IOI
35p
12.0%
10
IOI '11 P1 - Tropical Garden (Standard I/O)
IOI
25p
11.8%
167
IOI '16 P1 - Detecting Molecules
IOI
12p
11.8%
155
IOI '09 P7 - Regions
IOI
20p
11.8%
55
IOI '20 P3 - Carnival Tickets
IOI
20p
11.8%
37
IOI '18 P5 - Highway Tolls
IOI
30p
11.7%
14
IOI '12 P2 - Parachute Rings (Standard I/O)
IOI
25p
11.5%
111
IOI '15 P4 - Horses
IOI
15p
11.4%
102
IOI '17 P6 - Ancient Books
IOI
25p
11.4%
30
IOI '03 P5 - Amazing Robots
IOI
20
11.4%
38
IOI '14 P4 - Gondola
IOI
15p
11.1%
99
IOI '21 P2 - Keys
IOI
25p
10.9%
14
IOI '14 P1 - Rail
IOI
30p
10.7%
49
IOI '08 P2 - Islands
IOI
25p
10.7%
111
IOI '11 P5 - Dancing Elephants (Standard I/O)
IOI
20p
10.6%
93
IOI '05 Practice Task 3 - Polish Flag
IOI
20p
10.6%
4
IOI '17 P4 - The Big Prize
IOI
20p
10.5%
57
IOI '11 P5 - Dancing Elephants
IOI
40p
10.4%
42
«
1
2
3
4
»