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
6
...
99
100
»
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
CCC '24 J4 - Troublesome Keys
COCI '22 Contest 4 #1 7Krokods
CCC '24 S2 - Heavy-Light Composition
CCC '19 J3 - Cold Compress
CCC '24 J5 - Harvest Waterloo
COCI '23 Contest 5 #1 Zlagalica
CCC '24 S3 - Swipe
Problem
Category
Points
AC % ▾
Users
NOI '17 P5 - Vegetables
China NOI
25p
66.7%
4
DMOJ Capture The Flag '20 F2 - Queries & Strings
CTF
5
66.3%
50
COCI '09 Contest 1 #2 Domino
COCI
5
66.2%
375
VM7WC '16 #2 Bronze - G
VM7WC
5
66.2%
257
WC '17 Contest 1 J1 - Canadian Accent
Woburn Challenge
3
66.2%
556
ECOO '14 R1 P2 - Orphan Black
ECOO
5p
66.1%
35
WC '17 Contest 4 J1 - Fight or Flight
Woburn Challenge
3
66.0%
324
DWITE '09 R5 #1 - ASCII bar graphs
DWITE
3
66.0%
134
Ternary Search Tree
Uncategorized
5
65.9%
20
WC '18 Contest 2 J2 - This Message will Self-Destruct
Woburn Challenge
3p
65.8%
221
DWITE '09 R4 #1 - Social Media Overload
DWITE
3
65.7%
97
COCI '23 Contest 4 #1 Bingo
COCI
5p
65.7%
60
COCI '18 Contest 6 #1 Lun
COCI
5p
65.5%
19
UCRPC F21 A - Senseless Census
ICPC
5
65.5%
88
SAC '22 Code Challenge 5 P1 - Querying Plants
SAC Coding Challenge
3
65.4%
224
SAC '22 Code Challenge 3 Junior P1 - Normal Problem
SAC Coding Challenge
3p
65.2%
300
WC '16 Contest 4 J1 - Anyone Can Be Anything
Woburn Challenge
5p
65.1%
85
CCC '24 S2 - Heavy-Light Composition
CCC
5p
65.0%
351
WC '15 Contest 2 J2 - The Empire Strikes Back
Woburn Challenge
3
64.9%
288
DMOPC '14 Contest 5 P2 - Longest Tunnel
DMOPC
3p
64.9%
744
Magic Sequence
Olympiads School
7p
64.8%
91
Amplitude Hackathon '23 Practice Problem 4 - Gigatron Autoscaling
Uncategorized
3p
64.7%
25
DMOPC '19 Contest 6 P0 - Trivial Math
DMOPC
3
64.7%
582
COCI '15 Contest 6 #1 Bela
COCI
5
64.6%
65
COCI '07 Contest 2 #1 Bijele
COCI
3
64.5%
614
COCI '06 Contest 2 #4 Sjecišta
COCI
7
64.4%
391
WOSS Dual Olympiad 2021 J2/S1: Secret Formula
Seasonal
3
64.2%
262
BlueBook - Exact Divisors
BlueBook
3
64.1%
973
DWITE '06 R5 #4 - Connect-4
DWITE
7
64.0%
39
ECOO '21 P3 - Quintessential Questions
ECOO
3p
64.0%
221
WC '18 Contest 2 J1 - Alternate Access
Woburn Challenge
3p
63.9%
127
DWITE '08 R1 #1 - LaNDscAPE ii
DWITE
3
63.9%
53
Facebook Hacker Cup '19 Final Round P6 - Temporal Revision
FHC
40p
63.6%
5
Google Code Jam '09 Qualification Round Problem A - Alien Language
Google Code Jam
5p
63.6%
5
DMOJ Capture The Flag '20 F1 - RGB
CTF
3
63.5%
142
DWITE '09 R3 #2 - Rounding to Fibonacci
DWITE
5
63.4%
171
Waterloo 2022 Fall D - Course Selection
Waterloo Local
5
63.4%
49
COCI '11 Contest 2 #1 Najboljih 5
COCI
5p
63.4%
39
DMOPC '16 Contest 3 P0 - Negative Feedback
DMOPC
3
63.3%
504
Educational DP Contest AtCoder R - Walk
Uncategorized
15
63.3%
130
DWITE '08 R2 #4 - Big shiny tunes
DWITE
7
63.2%
79
Another Contest 4 Problem 5 - Prime Time Television
ACC
0
63.1%
157
Summer Institute '17 Contest 1 P10 - Trading Cards
SIUCF
3
63.0%
140
SAC '22 Code Challenge 4 Junior P1 - Obligatory DeMello Problem
SAC Coding Challenge
3
62.9%
227
COCI '17 Contest 5 #1 Olivander
COCI
5p
62.9%
61
COCI '20 Contest 4 #1 Pizza
COCI
5p
62.8%
151
COCI '14 Contest 3 #1 Strojopis
COCI
5p
62.7%
165
COCI '17 Contest 2 #1 Košnja
COCI
3
62.7%
112
COCI '17 Contest 3 #1 Aron
COCI
3
62.7%
100
BlueBook - Multiple
BlueBook
3
62.6%
1439
«
1
2
3
4
5
6
...
99
100
»