[ABC245B] Mex

[ABC245C] Choose Elements

[ABC245D] Polynomial division

[ABC245E] Wrapping Chocolate

贪心

[ABC245F] Endless Walk

拓扑排序 · 强连通分量

[ABC245G] Foreign Friends

最短路

[ABC245Ex] Product Modulo 2

中国剩余定理 CRT · 组合数学

[ABC246A] Four Points

[ABC246B] Get Closer

[ABC246C] Coupon

[ABC246D] 2-variable Function

数学 · 双指针 two-pointer

[ABC246E] Bishop 2

模拟 · 广度优先搜索 BFS · 剪枝

[ABC246F] typewriter

容斥原理

[ABC246G] Game on Tree 3

[ABC246Ex] 01? Queries

动态 DP

[ABC247A] Move Right

[ABC247B] Unique Nicknames

[ABC247C] 1 2 1 3 1 2 1

[ABC247D] Cylinder

[ABC247E] Max Min

[ABC247F] Cards

动态规划 DP · 并查集

[ABC247G] Dream Team

[ABC247Ex] Rearranging Problem

[ABC248A] Lacked Number

[ABC248B] Slimes

[ABC248C] Dice Sum

[ABC248D] Range Count Query

[ABC248E] K-colinear Line

[ABC248F] Keep Connect

动态规划 DP

[ABC248G] GCD cost on the tree

[ABC248Ex] Beautiful Subsequences

[ABC249A] Jogging

[ABC249B] Perfect String

[ABC249C] Just K

[ABC249D] Index Trio

[ABC249E] RLE

[ABC249F] Ignore Operations

[ABC249G] Xor Cards

[ABC249Ex] Dye Color

鞅的停时定理

[ABC250A] Adjacent Squares

[ABC250B] Enlarged Checker Board

[ABC250C] Adjacent Swaps

[ABC250D] 250-like Number

[ABC250E] Prefix Equality

哈希 hashing

[ABC250F] One Fourth

[ABC250G] Stonks

[ABC250Ex] Trespassing Takahashi

[ABC251A] Six Characters

[ABC251B] At Most 3 (Judge ver.)

[ABC251C] Poem Online Judge