Joking (Hard Version)

Joking (Easy Version)

Kazaee

树状数组 · 哈希 hashing · 随机化

Olympiad Training

Two Groups

数学 · 贪心

BAN BAN

贪心

Swap Game

博弈论

Yet Another Problem

数学 · 贪心 · 前缀和

List Generation

递推 · 组合数学 · 容斥原理

The Ultimate Square

Diverse Substrings

枚举

Zero-Sum Prefixes

贪心 · 前缀和

ConstructOR

贪心 · 中国剩余定理 CRT · 位运算 · 构造

Yet Another Array Counting Problem

动态规划 DP · 树形 DP · 笛卡尔树

Circular Xor Reversal

位运算 · 构造

Cowardly Rooks

Death's Blessing

Number Game

Counting Arrays

Cactus Wall

Distance to the Path

Indirect Sort

贪心

Maximum Substring

枚举

Complementary XOR

贪心

Count GCD

数学 · 枚举 · 容斥原理

Bracket Cost

线段树 · 树状数组

Majority

Doping

组合数学 · 容斥原理

BinaryStringForces

动态规划 DP · 动态规划优化

Make Nonzero Sum (hard version)

Make Nonzero Sum (easy version)

Factorial Divisibility

Wish I Knew How to Sort

动态规划 DP · 组合数学 · 概率论

The Beach

N Machines

Minecraft Series

Technical Support

Kevin and Permutation

SSeeeeiinngg DDoouubbllee

XOR = Average

Almost All Multiples

Range = √Sum

前缀和 · 构造

Tick, Tock

Decent Division

Yes-Yes?

字符串

Lost Permutation

Thermostat

Make It Round

The Humanoid

All Possible Digits