819. 最常见的单词
Easy | Array, Hash Table, String, Counting
Hash Table
820. 单词的压缩编码
Medium | Array, Hash Table, String, Trie
822. 翻卡片游戏
Medium | Array, Hash Table
828. 统计字符串中的唯一字符
Hard | Hash Table, String, Dynamic Programming
833. 字符串中的查找与替换
Medium | Array, Hash Table, String, Sorting
840. 网格中的幻方
Medium | Array, Hash Table, Math, Matrix
846. 同花顺
Medium | Array, Hash Table, Greedy, Sorting
854. K 相似字符串
Hard | Hash Table, String, Breadth-First Search
859. 亲密字符串
Easy | Hash Table, String
863. 二叉树中所有距离为 K 的结点
Medium | Hash Table, Tree, Depth-First Search, Breadth-First Search, Binary Tree
865. 包含所有最深节点的最小子树
Medium | Hash Table, Tree, Depth-First Search, Breadth-First Search, Binary Tree
869. 重新排列得到2的幂
Medium | Hash Table, Math, Sorting, Counting, Enumeration
873. 最长斐波那契数列的长度
Medium | Array, Hash Table, Dynamic Programming
874. 模拟行走机器人
Medium | Array, Hash Table, Simulation
884. 两句话中的不常见单词
Easy | Hash Table, String, Counting
888. 公平的糖果棒交换
Easy | Array, Hash Table, Binary Search, Sorting
889. 根据前序和后序遍历构造二叉树
Medium | Array, Hash Table, Divide and Conquer, Tree, Binary Tree
890. 查找和替换模式
Medium | Array, Hash Table, String
895. 最大频率栈
Hard | Hash Table, Stack, Design, Ordered Set
911. 在线选举
Medium | Array, Hash Table, Binary Search, Design