Reverse a Substring

Game with Telephone Numbers

Alarm Clocks Everywhere

Beautiful Array

Guess the Root

Delivery Oligopoly

图论 · 双连通分量 · 状压 DP

Inscribed Figures

Ugly Pairs

Match Points

0-1-Tree

Special Segments of Permutation

分治 · 笛卡尔树

Card Bag

动态规划 DP · 前缀和 · 概率论

Optimizer

Reachable Numbers

Long Number

Increasing Subsequence (hard version)

贪心

Increasing Subsequence (easy version)

N Problems During K Days

Minimum Array

Maximum Balanced Circle

Inverse of Rows and Columns

The Party and Sweets

The minimal unique substring

字符串 · 构造

Permutation recovery

Winding polygonal line

Strange device

Density of subarrays

A pile of stones

Expansion coefficient of the array

Zoning Restrictions Again

Double Matrix

Eating Soup

Cat Party (Hard Edition)

Cat Party (Easy Edition)

Power Transmission (Hard Edition)

Power Transmission (Easy Edition)

Mysterious Code

动态规划 DP · AC 自动机 · KMP 算法

Magical Permutation

Indecisive Taxi Fee

Remainder

Polycarp Training

Good String

Almost All Divisors

Two Arrays and Sum of Functions

数学 · 排序

Microtransactions (hard version)

贪心 · 二分

Microtransactions (easy version)

贪心

Silent Classroom

All the Vowels Please

A Tale of Two Lands

Cute Sequences