April Fools' Problem (hard)

反悔贪心

April Fools' Problem (easy)

April Fools' Problem (medium)

反悔贪心

Maximal Binary Matrix

贪心 · 递归

Distances to Zero

Maximal GCD

Magazine Ad

二分

Roma and Poker

动态规划 DP · 图论 · 差分约束 · 构造

Coprime Subsequences

莫比乌斯反演 · 容斥原理

Periodic RMQ Problem

线段树 · ST 表

Find Amir

Minimum number of steps

Ice cream coloring

Expected diameter of a tree

树的直径 · 前缀和 · 期望

The same permutation

Fake bullions

Fake NP

素数判断,质数,筛法

3-palindrome

字符串 · 构造

Is it rated?

T-Shirt Hunt

Lucky Year

Average Sleep Time

Tea Party

贪心

Array Division

模拟 · 二分 · STL

Selling Souvenirs

动态规划 DP · 贪心 · 二分 · 排序 · 分类讨论 · 反悔贪心

Card Game

Anthem of Berland

动态规划 DP · KMP 算法

Do you want a date?

Glad to see you!

Find a car

Hitchhiking in the Baltic States

动态规划 DP · 平衡树 · 枚举

Surprise me!

数学 · 数论 · 分治

Straight «A»

Summer sell-off

Vladik and Courtesy

Vladik and Complicated Book

枚举

Vladik and Memorable Trip

Vladik and Favorite Game

Vladik and Entertaining Flags

Sagheer and Crossroads

Sagheer, the Hausmeister

Sagheer and Nubian Market

贪心 · 二分

Sagheer and Kindergarten

Sagheer and Apple Tree

The Contest

The Golden Age

The Tag Game

图论 · 博弈论 · 深度优先搜索 DFS

Two Melodies

Army Creation

Bipartite Checking