One and Two

Sum of Two Numbers

Matching Numbers

Moving Dots

Sum Over Zero

XOR, Tree, and Queries

Serval and Mocha's Array

Serval and Inversion Magic

Serval and Toxel's Arrays

Serval and Shift-Shift-Shift

Serval and Music Game

Serval and Brain Power

搜索 · 分类讨论

Polycarp and the Day of Pi

Taisia and Dice

Premutation

Matryoshkas

Vlad and a Pair of Numbers

数学

Timofey and Black-White Tree

Tokens on Graph

Codeforces Checking

Following Directions

Prepend and Append

Distinct Split

Negatives and Positives

Range Update Point Query

Teleporters (Hard Version)

Teleporters (Easy Version)

GamingForces

Stand-up Comedian

Min Max Sort

Fixed Prefix Permutations

Divisors and Table

数论 · 素数判断 · 构造

Graph Coloring (hard version)

动态规划 DP · 图论 · 组合数学 · 快速数论变换 NTT

Graph Coloring (easy version)

动态规划 DP · 图论 · 组合数学

Yet Another Promotion

数学 · 贪心

Fedya and Array

构造

Dora and Search

贪心 · 双指针 two-pointer

Moscow Gorillas

数学 · 组合数学

Velepin and Marketing

Rebrending

莫队 · 树状数组 · 排序 · 分块 · 扫描线 · 根号分治 · 单调栈 · 离线处理

Prefix and Suffix Array

Not Dividing

Scoring Subsequences

Counting Factorizations

Labeling the Tree with Distances

树形 DP · 哈希 hashing

Two Towers

Ideal Point

Tea Tasting

Triangle Coloring

Explosions?