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Hot problems
CCC '12 S3 - Absolutely Acidic
DMOPC '20 Contest 4 P1 - Missing Numbers
CCC '21 J3 - Secret Instructions
CCC '24 S2 - Heavy-Light Composition
COCI '06 Regional #3 Firefly
ACSL '09 Practice P4 - Rank
ECOO '19 R1 P1 - Free Shirts
Problem
Category
Points ▴
AC %
Users
Mock CCC '22 Contest 1 J5 - New Year's Restrictions
Mock CCC
7p
24.9%
143
Yet Another Contest 1 P1 - Mixed Doubles
YAC
7p
16.5%
225
Baltic OI '10 P4 - Matching Bins
Baltic OI
7p
20.8%
26
Mock CCC '22 Contest 2 J4 - Hockey Bracket
Mock CCC
7p
18.4%
194
Factors
Uncategorized
7
9.2%
46
DMOPC '21 Contest 6 P2 - Gacha Luck
DMOPC
7p
29.1%
295
An Animal Contest 6 P2 - G-Pop
AAC
7p
10.7%
123
SAC '22 Code Challenge 4 Junior P4 - Obligatory Permutation Problem
SAC Coding Challenge
7p
18.4%
93
Yet Another Contest 2 P2 - Secret Sequence
YAC
7p
26.3%
132
COCI '21 Contest 5 #1 Kemija
COCI
7p
39.0%
97
DMOPC '21 Contest 7 P2 - Knitting Scarves
DMOPC
7
24.3%
184
Intertwined Strings
Uncategorized
7p
42.5%
143
Magic Sequence
Olympiads School
7p
64.9%
92
A Math Contest P3 - LIS Reconstruction
Uncategorized
7
47.0%
160
Cheerio Contest 1 S3 - Stock Trading
Uncategorized
7p
26.0%
52
Another Random Contest 1 P3 - Physics Olympics
Uncategorized
7p
31.3%
32
Another Random Contest 1 P2 - Two Sequences
Uncategorized
7p
18.9%
43
DMOPC '21 Contest 8 P1 - Peanut Planning
DMOPC
7p
19.7%
212
DMOPC '21 Contest 9 P2 - String Puzzle
DMOPC
7p
24.7%
152
DMOPC '21 Contest 9 P1 - Board Numbers
DMOPC
7p
17.5%
179
COCI '17 Contest 1 #3 Lozinke Hard
COCI
7
24.7%
56
SAC '22 Code Challenge 5 Junior P4 - Course Requirements
SAC Coding Challenge
7p
52.8%
239
Yet Another Contest 4 P2 - Alchemy 2
YAC
7p
26.3%
164
Cheerio Contest 1 S2 - School Expansion
Uncategorized
7p
31.0%
101
NOIP '99 P2 - Palindrome Numbers
China NOI
7p
14.1%
25
A Math Contest P5 - Good Arrays
Uncategorized
7p
29.6%
129
Yet Another Contest 6 P2 - No More Telemarketers
YAC
7p
16.7%
128
A Math Contest P4 - Circle Cutting
Uncategorized
7
40.9%
105
Lemon Game
Olympiads School
7
28.6%
43
DMOPC '21 Contest 10 P2 - Cycle Sort
DMOPC
7p
11.5%
152
Baltic OI '11 P6 - Plagiarism
Baltic OI
7p
27.4%
38
Baltic OI '14 P2 - Three Friends
Baltic OI
7p
19.3%
45
Baltic OI '06 P6 - Jump
Baltic OI
7p
15.3%
22
Another Contest 9 Problem 2 - Counting Down the Days
ACC
7
6.9%
61
Baltic OI '04 P1 - Ships
Baltic OI
7p
14.4%
12
An Animal Contest 7 P2 - Squirrel Structures
AAC
7p
15.2%
138
Bit Combinations
Uncategorized
7
33.3%
16
NOIP '18 Junior P2 - The Big Battle
China NOI
7p
33.3%
13
BSSPC '22 P5 - Derrick and Orz Trees
Uncategorized
7p
19.4%
140
Purple Lemon
Uncategorized
7p
21.4%
17
Yet Another Contest 5 P1 - Number Pyramid
YAC
7p
18.9%
186
SGS Programming Challenge P1 - XOR in Computer Class
Uncategorized
7p
13.3%
156
MCIPC Contest 1 P5 - Rainwater
Uncategorized
7
21.1%
17
MCIPC Contest 1 P4 - Snack Line
Uncategorized
7p
14.5%
14
Cheerio Contest 2 P5 - Subsequence Queries
Uncategorized
7p
26.5%
23
Cheerio Contest 2 P4 - Modulus Finding
Uncategorized
7p
14.5%
18
Max's Anger Contest Series 1 P3 - Divide and Connor
Seasonal
7
23.6%
217
Yet Another Contest 8 P2 - No More Modern Art
YAC
7p
27.4%
245
MCIPC Contest 2 P4 - Wreath
Uncategorized
7p
9.6%
8
DMOPC '22 Contest 2 P2 - Line Trace
DMOPC
7p
34.1%
167
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