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Random
Hot problems
DMOPC '18 Contest 4 P3 - Dr. Henri and Ionization
CCC '25 J3 - Product Codes
DMOPC '15 Contest 7 P6 - A Very Very Original Problem
Canada Day Contest 2021 - CCC Bad Haha
CCC '23 S2 - Symmetric Mountains
CCC '21 S2 - Modern Art
CCC '13 S1 - From 1987 to 2013
Problem
Category
Points
AC %
Users
HCI '16 - Unexpected Factorial
Uncategorized
5p
27.6%
88
HCI '16 - Ulam Spiral
Uncategorized
5p
18.7%
47
HCI '16 - Wizardry
Uncategorized
7
5.2%
21
HCI '16 - Xorpow
Uncategorized
10p
25.0%
102
The Heist
Uncategorized
10p
23.0%
29
Hello, World!
Uncategorized
3
56.6%
13820
Hello, World! (Hard)
Uncategorized
0
6.3%
635
Hello, World! (Harder)
Uncategorized
40p
0.8%
3
HHPC1 P1 - Yielding the Longest Substring
Uncategorized
5
22.7%
230
HHPC1 P2 - Yuniformity Challenge
Uncategorized
10p
14.0%
148
HHPC1 P3 - Yonder Ridge
Uncategorized
12p
11.6%
33
HHPC1 P4 - Yet Another A+B Problem
Uncategorized
10p
13.9%
133
HHPC1 P5 - Yunity Grouping Objects
Uncategorized
17p
33.7%
15
HHPC1 P6 - Yarn Street's Strategic Shopping
Uncategorized
20p
8.3%
5
CCCHK '08 J1 - Best fish
CCC
3p
39.8%
938
CCCHK '08 J2 - Lucky Number
CCC
3p
27.0%
982
CCCHK '08 J3 - Phone book
CCC
5p
35.5%
769
CCCHK '08 J4 - Tic-tac-toe
CCC
5p
12.5%
140
CCCHK '15 J1 - Rock-paper-scissors
CCC
3p
52.6%
961
CCCHK '15 J2 - What is the minimum area?
CCC
5p
35.7%
310
CCCHK '15 J3 - Queens can't attack me!
CCC
5p
50.8%
722
CCCHK '15 J4 - Where to build my house?
CCC
5p
19.0%
330
CCCHK '15 J5 - No friends in the same group.
CCC
15p
10.5%
40
CCCHK '15 S1 - Finding number of pairs
CCC
7p
15.5%
211
CCCHK '15 S2 - Matching Problem
CCC
10p
8.8%
48
CCCHK '15 S3 - Symmetric Cross
CCC
12p
22.7%
38
CCCHK '15 S4 - When to meet?
CCC
15p
32.0%
35
CCCHK '15 S5 - Can I pass the courses?
CCC
25p
5.2%
9
Homer Simpson
Uncategorized
3
30.5%
29
HopScotch II
Classics
12p
23.8%
208
Hungry
Uncategorized
5p
45.3%
124
The Hu Tao Fractal
Uncategorized
7p
17.2%
14
Icebergs
Uncategorized
12p
19.1%
56
ICHB Selection Contest '17 Problem 1 - Airship Fights (Correct Version)
Uncategorized
30p
7.7%
3
ICHB Selection Contest '17 Problem 2 - Black Star's Visit
Uncategorized
7p
8.8%
28
ICHB Selection Contest '17 Problem 3 - Parallel Universe
Uncategorized
12p
23.0%
170
Word Scrambler
Uncategorized
5
49.9%
785
Imaginary Units
Uncategorized
10p
24.4%
5
Inaho X
Uncategorized
7p
33.9%
13
Inaho XI
Uncategorized
5p
43.5%
31
Inaho II
Uncategorized
25p
13.5%
32
Inaho III
Uncategorized
17p
18.6%
33
Inaho IV
Uncategorized
5p
49.1%
166
Inaho V
Uncategorized
3p
19.1%
220
Inaho VI
Uncategorized
10p
31.2%
44
Inaho VII
Uncategorized
25p
23.9%
9
Inaho VIII
Uncategorized
20
26.7%
11
Inaho IX
Uncategorized
20p
25.3%
54
Infinity
Uncategorized
3
35.9%
566
Cosmic Inflation
Uncategorized
7
47.9%
31
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