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
...
94
95
96
97
98
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
ECOO '13 R1 P1 - Take a Number
DWITE '10 R3 #3 - Dominos Tiling
CCC '04 S2 - TopYodeller
An Animal Contest 2 P3 - Koala Balloons
CCC '24 J5 - Harvest Waterloo
TSS Club Fair 2017 Problem B
CCC '97 S3 - Double Knockout Competition
Problem
Category
Points
AC %
Users ▴
Hailstone Numbers
Uncategorized
3
57.0%
807
CCC '23 S2 - Symmetric Mountains
CCC
7p
26.5%
815
CCC '05 S4 - Pyramid Message Scheme
CCC
10
35.7%
819
Mock CCC '20 Contest 1 J1 - A Rage Tree Problem
Mock CCC
3p
48.3%
826
IOI '00 P1 - Palindrome
IOI
10p
18.5%
830
Educational DP Contest AtCoder C - Vacation
Uncategorized
7
59.6%
832
BlueBook - Leap Year
BlueBook
3
37.8%
837
Longest Common Subsequence
Classics
7
40.6%
838
CCC '20 S3 - Searching for Strings
CCC
12p
8.9%
843
ECOO '17 R1 P1 - Munch 'n' Brunch
ECOO
5p
17.9%
844
CCCHK '08 J2 - Lucky Number
CCC
3
26.8%
845
List Minimum (Easy)
Uncategorized
3p
11.9%
851
CCCHK '15 J1 - Rock-paper-scissors
CCC
3
51.7%
854
ACSL '09 Practice P4 - Rank
Uncategorized
7
45.9%
855
ACM U of T Tryouts C1 A - Rock Paper Scissors Fox
ICPC
3
49.3%
859
DMOPC '14 Contest 3 P1 - Not Enough Users!
DMOPC
3p
48.6%
860
Educational DP Contest AtCoder B - Frog 2
Uncategorized
7
43.1%
861
CCC '07 S5 - Bowling for Numbers
CCC
10p
29.9%
868
COCI '06 Contest 2 #2 ABC
COCI
3
45.6%
868
PEG Test '14 - Water
Uncategorized
3
54.6%
870
BlueBook - Direction
BlueBook
3
40.8%
871
DMOPC '14 Contest 1 P3 - New Students
DMOPC
3p
37.5%
877
Disjoint Set Test
Data Structure Tests
10
37.1%
885
CCC '08 J4 - From Prefix to Postfix
CCC
7
42.8%
888
CCC '02 S4 - Bridge Crossing
CCC
10p
37.2%
888
Binary
Uncategorized
5
24.1%
889
GFSSOC '14 Winter J1 - Flying Plushies
GFSSOC
3p
50.7%
889
IOI '04 P4 - Phidias
IOI
10p
53.6%
889
CCC '09 S2 - Lights Going On and Off
CCC
10
40.6%
902
ECOO '19 R1 P1 - Free Shirts
ECOO
5p
31.2%
903
Prime Factorization
Uncategorized
5
25.2%
904
CCC '01 S2 - Spirals
CCC
5
41.2%
912
Back To School '16: Harambe
Seasonal
3p
30.5%
913
The Cosmic Era P2 - Uneven Sand
Uncategorized
5
24.6%
925
STNBD P1 - Ren Ashbell
Uncategorized
3p
29.3%
945
CCC '16 S4 - Combining Riceballs
CCC
15p
28.9%
947
Mock CCC '19 Contest 1 J1 - Pusheen's Report Card
Mock CCC
3p
36.1%
970
BlueBook - Exact Divisors
BlueBook
3
64.2%
979
ACM U of T Tryouts C0 A - Max Flow
ICPC
3
60.4%
984
COCI '12 Contest 5 #1 Ljestvica
COCI
5p
19.3%
984
The Cosmic Era P3 - Battle Positions
Uncategorized
7
30.5%
988
CCO '07 P2 - Snowflakes
CCO
10
14.6%
989
CCC '99 S1 - Card Game
CCC
5
31.3%
1001
CCC '11 J5 - Unfriend
CCC
7
46.8%
1003
CCC '21 S3 - Lunch Concert
CCC
10p
24.6%
1018
CCC '97 S1 - Sentences
CCC
5
29.4%
1021
LKP '18 Contest 2 P1 - Food Lines
Uncategorized
3
37.8%
1033
CCC '09 S4 - Shop and Ship
CCC
10
21.0%
1034
COCI '18 Contest 4 #1 Elder
COCI
5p
36.9%
1038
Educational DP Contest AtCoder D - Knapsack 1
Uncategorized
7
38.8%
1045
«
1
2
...
94
95
96
97
98
99
100
»