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
CCC '24 S2 - Heavy-Light Composition
APIO '10 P1 - Commando
SAC '22 Code Challenge 5 P2 - Querying Extensions
Max's Anger Contest Series 2 P3 - Array Anger
CCC '12 S2 - Aromatic Numbers
CCO '07 P2 - Snowflakes
CCC '15 S3 - Gates
Problem
Category
Points
AC %
Users ▴
DWITE '09 R3 #1 - Quiz Time
DWITE
3
46.1%
97
DWITE '07 R1 #3 - Where's my QWERTY?
DWITE
3
41.3%
98
DWITE '09 R4 #1 - Social Media Overload
DWITE
3
65.9%
100
DWITE '06 R5 #3 - UPC Check Digit
DWITE
5
38.0%
100
DWITE '12 R2 #1 - Sugar Rush
DWITE
3
30.4%
101
DWITE '07 R5 #3 - Parity bit
DWITE
5
71.0%
102
DWITE '08 R1 #2 - Simple Checksum
DWITE
3
51.0%
103
DWITE '09 R1 #4 - My First True Letter
DWITE
3
38.1%
104
DWITE '09 R7 #1 - Binary Equipment
DWITE
3
43.2%
105
DWITE '06 R5 #2 - Floppy Disk
DWITE
7p
56.4%
106
DWITE '10 R5 #5 - Cube World
DWITE
12
26.3%
111
DWITE '02 R2 #2 - The Five M's of Stats 101
DWITE
5
31.1%
111
DWITE '11 R1 #2 - Penny Game
DWITE
5
24.3%
112
DWITE '12 R2 #3 - Bitstrings
DWITE
3
34.8%
117
DWITE '09 R6 #5 - Air Travel Planning
DWITE
7
61.0%
118
DWITE '07 R2 #3 - Floor Plan
DWITE
7
67.5%
124
DWITE '10 R3 #4 - Forest Fires
DWITE
7
39.8%
129
DWITE '02 R2 #5 - Now I know my ABCs
DWITE
5
38.9%
132
DWITE '12 R5 #2 - Copycat SMS
DWITE
5
29.8%
135
DWITE '10 R1 #3 - Power tiles
DWITE
5
68.7%
135
DWITE '09 R5 #1 - ASCII bar graphs
DWITE
3
66.2%
136
DWITE '11 R5 #1 - Age Gate
DWITE
3
40.4%
139
DWITE '07 R3 #3 - Playlist
DWITE
7
43.8%
146
DWITE '11 R1 #5 - Tattarrattat
DWITE
10
59.0%
147
DWITE '08 R5 #1 - Baby Diff
DWITE
3
56.7%
148
DWITE '09 R2 #4 - Breadth First Not Quite Tree
DWITE
5
33.4%
150
DWITE '07 R2 #2 - Show Me The Money!
DWITE
3
34.8%
151
DWITE '08 R1 #4 - What is this Roman Numeral
DWITE
7
62.0%
155
DWITE '07 R3 #1 - Yet Another Primes Question
DWITE
5
58.2%
156
DWITE '08 R4 #4 - Shortest path around v2
DWITE
7
46.8%
157
DWITE '11 R2 #5 - Portals Check
DWITE
7
13.7%
160
DWITE '12 R5 #3 - Triangle Count
DWITE
7
33.4%
162
DWITE '10 R5 #3 - Balancing Act
DWITE
7
39.3%
165
DWITE '09 R3 #2 - Rounding to Fibonacci
DWITE
5
63.4%
171
DWITE '09 R6 #2 - Round to power of two
DWITE
3
50.3%
181
DWITE '07 R4 #4 - Shortest path around
DWITE
7
42.4%
187
DWITE '09 R6 #4 - Time for Change
DWITE
7
57.9%
209
DWITE '10 R1 #1 - Age Gate
DWITE
3
33.1%
210
DWITE '12 R2 #4 - Magic Trick
DWITE
7
42.1%
212
DWITE '10 R5 #2 - Safe from Rooks
DWITE
5
32.5%
212
DWITE '06 R5 #5 - Prime Palindromes
DWITE
10
24.6%
212
DWITE '07 R3 #2 - There's An Essay In My Code
DWITE
5
30.2%
222
DWITE '09 R1 #2 - Word Scrambler
DWITE
5
57.0%
223
DWITE '09 R5 #2 - Round to Second Prime
DWITE
5
57.2%
250
DWITE '07 R2 #4 - All Is Balanced
DWITE
5
23.3%
253
DWITE '07 R1 #4 - Stacks of Blocks
DWITE
5
36.3%
255
DWITE '09 R1 #3 - That Missing Number
DWITE
5
52.7%
257
DWITE '11 R4 #2 - Prime Time
DWITE
5
49.9%
263
DWITE '12 R1 #4 - Trick or Tree'ing
DWITE
5
23.3%
264
DWITE '10 R3 #3 - Dominos Tiling
DWITE
10
46.3%
266
«
1
2
3
4
»