Small Permutation Problem (Easy Version)

递推

Pumping Lemma

字符串

Parallel Swaps Sort

Short Permutation Problem

动态规划 DP · 组合数学 · 快速数论变换 NTT

Accumulator Apex

Blueprint for Seating

Divisibility Test

数论 · 进制

Evaluate It and Back Again

Fugitive Frenzy

Hypercatapult Commute

Kim's Quest

LOL Lovers

枚举 · 前缀和

Rating Increase

Swap and Delete

Game with Multiset

Array Collapse

动态规划 DP · 单调栈

Matrix Problem

网络流 · 费用流

Palindromic Problem

字符串 · 枚举

Problemsolving Log

Preparing for the Contest

构造

Quests

贪心 · 枚举

Three Activities

枚举

Game with Marbles (Hard Version)

贪心 · 博弈论

Game with Marbles (Easy Version)

贪心 · 博弈论

Programming Competition

动态规划 DP · 贪心 · 树形 DP

Light Bulbs (Hard Version)

Light Bulbs (Easy Version)

Odd One Out

模拟

Not Quite Latin Square

模拟

Can I Square?

模拟

Unnatural Language Processing

模拟

Romantic Glasses

前缀和

Greetings

树状数组

Bicycles

最短路

2023

数学

Two Divisors

最大公约数 gcd

Training Before the Olympiad

博弈论

Mathematical Problem

枚举

Happy Life in University

线段树 · 深度优先搜索 DFS

Group Division

图论

Optimizations From Chelsu

点分治

Matrix Rank (Hard Version)

线性代数

Matrix Rank (Easy Version)

线性代数

Least Product

数学

Erase First or Second Letter

枚举

Watering an Array

贪心

Yet Another Inversions Problem

树状数组

Construct Matrix

构造

Construct Tree

动态规划 DP

Brick Wall