[ABC421D] RLE Moving

模拟 · 分类讨论

[ABC421E] Yacht

动态规划 DP · 搜索 · 记忆化搜索 · 期望

[ABC421F] Erase between X and Y

链表

[ABC421G] Increase to make it Increasing

费用流

[ABC422A] Stage Clear

[ABC422B] Looped Rope

模拟 · 字符串 · 枚举

[ABC422C] AtCoder AAC Contest

贪心

[ABC422D] Least Unbalanced

构造

[ABC422E] Colinear

分治 · 随机化

[ABC422F] Eat and Ride

动态规划 DP · 最短路

[ABC422G] Balls and Boxes

动态规划 DP · 组合数学 · 生成函数 · 快速数论变换 NTT · 根号分治

[ABC423A] Scary Fee

数学 · 枚举

[ABC423B] Locked Rooms

模拟

[ABC423C] Lock All Doors

贪心

[ABC423D] Long Waiting

模拟 · 堆 · 优先队列

[ABC423E] Sum of Subarrays

数学 · 前缀和

[ABC423F] Loud Cicada

组合数学 · 容斥原理

[ABC423G] Small Multiple 2

[ABC424A] Isosceles

[ABC424B] Perfect

模拟

[ABC424C] New Skill Acquired

搜索

[ABC424D] 2x2 Erasing 2

深度优先搜索 DFS · 剪枝 · 状压 DP

[ABC424E] Cut in Half

模拟 · 优先队列

[ABC424F] Adding Chords

线段树 · 哈希 hashing

[ABC424G] Set list

[ABC425A] Sigma Cubes

[ABC425B] Find Permutation 2

[ABC425C] Rotate and Sum Query

前缀和

[ABC425D] Ulam-Warburton Automaton

广度优先搜索 BFS

[ABC425E] Count Sequences 2

数学 · 中国剩余定理 CRT · 组合数学

[ABC425F] Inserting Process

状压 DP

[ABC425G] Sum of Min of XOR

字典树 Trie · 位运算

[ABC426A] OS Versions

[ABC426B] The Odd One Out

[ABC426C] Upgrade Required

模拟

[ABC426D] Pop and Insert

递推

[ABC426E] Closest Moment

二分 · 三分 · 平面几何

[ABC426F] Clearance

线段树

[ABC426G] Range Knapsack Query

分治 · 背包 DP

[ABC427A] ABC -> AC

模拟

[ABC427B] Sum of Digits Sequence

模拟

[ABC427C] Bipartize

图论 · 位运算

[ABC427D] The Simple Game

动态规划 DP · 博弈论 · 记忆化搜索

[ABC427E] Wind Cleaning

广度优先搜索 BFS · 记忆化搜索

[ABC427F] Not Adjacent

折半搜索 meet in the middle

[ABC427G] Takahashi's Expectation 2

二分 · 平衡树 · 分块

[ABC428A] Grandma's Footsteps

模拟

[ABC428B] Most Frequent Substrings

模拟 · 排序

[ABC428C] Brackets Stack Query

[ABC428D] 183184

数学