[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

贪心 · 堆

[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

[ABC251D] At Most 3 (Contestant ver.)

构造

[ABC251E] Takahashi and Animals

动态规划 DP

[ABC251F] Two Spanning Trees

图论 · 广度优先搜索 BFS · 深度优先搜索 DFS · 生成树 · 构造

[ABC251G] Intersection of Polygons

[ABC251Ex] Fill Triangle

[ABC252A] ASCII code

[ABC252B] Takahashi's Failure

[ABC252C] Slot Strategy

[ABC252D] Distinct Trio

[ABC252E] Road Reduction

图论 · 最短路 · 生成树

[ABC252F] Bread

贪心

[ABC252G] Pre-Order

动态规划 DP · 区间 DP

[ABC252Ex] K-th beautiful Necklace

[ABC253A] Median?

[ABC253B] Distance Between Tokens

[ABC253C] Max - Min Query

[ABC253D] FizzBuzz Sum Hard

[ABC253E] Distance Sequence

动态规划 DP · 前缀和

[ABC253F] Operations on a Matrix

线段树 · 树状数组

[ABC253G] Swap Many Times

[ABC253Ex] We Love Forest

集合幂级数，子集卷积 · 状压 DP

[ABC254A] Last Two Digits

[ABC254B] Practical Computing

[ABC254C] K Swap

[ABC254D] Together Square

[ABC254E] Small d and k

图论 · 枚举