[ARC217C] Greedy Customers 2

动态规划 DP · 区间 DP · 组合数学

[ARC217D] Greedy Customer

并查集 · 平衡树 · 动态规划优化 · 可持久化 · ST 表 · 均摊分析 · 单调栈

[ARC217E] Tree Growing

[ARC218A] Many Sets

组合数学

[ARC218B] All Minus

博弈论

[ARC218C] Amidakuji

构造

[ARC218D] I like Increasing

[ARC218E] Reverse and Reverse

[ARC218F] Buckets

[ARC218F2] Buckets

[ARC219A] Similarity

搜索 · 贪心 · 分治 · 字典树 Trie · 构造

[ARC219B] Reverse Permutation

[ARC219C] Traveling Door-to-Door Salesman (Elevator)

动态规划 DP · 贪心

[ARC219D] Grid Game

博弈论

[ARC219E] Equal Distribution

构造

[ARC219F] Range Division

[ARC219G] Traveling Door-to-Door Salesman (Stairs)

[ARC220A] Sum of Reciprocals of Squares

[ARC220B] Incomplete Shuffle

并查集 · 欧拉回路

[ARC220C] Range Increment

动态规划 DP · 贪心 · 堆 · 斜率维护技巧 slope trick · 反悔贪心

[ARC220D] Long Trail

数学 · 图论 · 构造 · Ad-hoc

[ARC220E] popcount ≥ K

[ARC221A] Two Arithmetic Progressions

最大公约数 gcd · 扩展欧几里德算法 · 莫比乌斯反演 · 容斥原理

[ARC221B] Two-Powered Sum

动态规划 DP · 组合数学 · 容斥原理 · Stirling 数

[ARC221C] Two Deques Sorting

线段树 · 区间 DP · 动态规划优化 · 扫描线

[ARC221D] Two Balanced Subtrees

构造 · Ad-hoc

[ARC221E] Two Increasing Sequences

[ARC222A] Colorful Intervals

构造

[ARC222B] Circular RPS

分类讨论

[ARC222C] 2 Directions vs 4 Directions

动态规划 DP

[ARC222D] Shift and Add

状压 DP

[ARC222E] XOR Matching

快速沃尔什变换 FWT

[ARC222F] Triple Transformation

大步小步算法 BSGS

[ARC223A] Unusual-Constraint Knapsack

[ARC223B] Valid Arrays by K-Divisible Swaps

排列组合

[ARC223C] Whole Product of Pairwise Distances

树状数组

[ARC223D] Xpectation of Cards in Hand with Laboratory

组合数学

[ARC223E] Yin-Yang Two Bits Insertion

[ARC223F] Zonal Score Maximization

动态规划 DP · 多项式 · 分治 · 动态规划优化

[ARC224A] Attach 00

枚举

[ARC224B] Adjacent Tiles

数学

[ARC224C] Ascending Labels

深度优先搜索 DFS · 构造

[ARC224D] Angst for All Pairs

贪心

[ARC224E] ABC|AB|A

贪心 · 栈

[ARC224F] AND/OR

组合数学 · 位运算

[ARC225A] Four Coloring

构造

[ARC225B] Independent Nim

博弈论

[ARC225C] K Spanning Tree

并查集 · 凸完全单调性（wqs 二分） · 生成树

[ARC225D] Gap Swap (easy)

[ARC225E] Gap Swap (hard)

Ad-hoc