225. 用队列实现栈
Easy | Stack, Design, Queue
Design
232. 用栈实现队列
Easy | Stack, Design, Queue
284. 支持预览功能的迭代器
Medium | Array, Design, Iterator
295. 数据流的中位数
Hard | Two Pointers, Design, Sorting, Heap (Priority Queue), Data Stream
297. 序列化和反序列化二叉树
Hard | String, Tree, Depth-First Search, Breadth-First Search, Design, Binary Tree
303. 区间和检索 - 数组不可变
Easy | Array, Design, Prefix Sum
304. 二维区域和检索 - 矩阵不可变
Medium | Array, Design, Matrix, Prefix Sum
307. 区域和检索 - 数组可修改
Medium | Array, Divide and Conquer, Design, Binary Indexed Tree, Segment Tree