截止至今LeetCode题目总量已经有1582题，估计将来每年平均增长300题左右，大部分人肯定是刷不完的，所以得有选择地刷LeetCode。

一种公认的刷题策略是按类别刷题，可是每个类别也有许多题，在有限的时间里到底该刷哪些题呢？个人根据LeetCode官方给出的每个题目的出现频率，整理并收录了每个类别里高频出现的题目，对于官方统计频率太低的题目，不予收录，最终得到了这个高频题目表格。

例如，对于下图中题号#275与#270的题目将被收录，并且#275出现频率大于#270；而对于题号#1011与#1182的题目，因为出现频率太低，将不被收录：

撸起键盘加油干！祝大家成功上岸！整理不易，点个赞吧！

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树结构篇-82题(Tree, 82 problems)

数据日期： 2020/03/26 (此时LeetCode题目数量：1582)
数据来源： LeetCode官方，将不同类别的题目按照官方给的出现频率(Frequency)降序排列，取有频率统计的题。

排序	题号	题目	通过率	难度
1	#95	Unique Binary Search Trees II	0.623	中等
2	#94	Binary Tree Inorder Traversal	0.707	中等
3	#96	Unique Binary Search Trees	0.652	中等
4	#226	Invert Binary Tree	0.745	简单
5	#104	Maximum Depth of Binary Tree	0.726	简单
6	#108	Convert Sorted Array to Binary Search Tree	0.699	简单
7	#617	Merge Two Binary Trees	0.755	简单
8	#107	Binary Tree Level Order Traversal II	0.647	简单
9	#543	Diameter of Binary Tree	0.49	简单
10	#114	Flatten Binary Tree to Linked List	0.681	中等
11	#105	Construct Binary Tree from Preorder and Inorder Traversal	0.646	中等
12	#101	Symmetric Tree	0.506	简单
13	#687	Longest Univalue Path	0.394	简单
14	#654	Maximum Binary Tree	0.798	中等
15	#655	Print Binary Tree	0.553	中等
16	#449	Serialize and Deserialize BST	0.51	中等
17	#199	Binary Tree Right Side View	0.639	中等
18	#257	Binary Tree Paths	0.63	简单
19	#102	Binary Tree Level Order Traversal	0.613	中等
20	#144	Binary Tree Preorder Traversal	0.648	中等
21	#669	Trim a Binary Search Tree	0.646	简单
22	#538	Convert BST to Greater Tree	0.596	简单
23	#124	Binary Tree Maximum Path Sum	0.397	困难
24	#112	Path Sum	0.493	简单
25	#145	Binary Tree Postorder Traversal	0.707	困难
26	#501	Find Mode in Binary Search Tree	0.441	简单
27	#100	Same Tree	0.569	简单
28	#530	Minimum Absolute Difference in BST	0.56	简单
29	#222	Count Complete Tree Nodes	0.678	中等
30	#111	Minimum Depth of Binary Tree	0.418	简单
31	#637	Average of Levels in Binary Tree	0.637	简单
32	#437	Path Sum III	0.545	简单
33	#173	Binary Search Tree Iterator	0.718	中等
34	#337	House Robber III	0.564	中等
35	#653	Two Sum IV - Input is a BST	0.544	简单
36	#404	Sum of Left Leaves	0.542	简单
37	#110	Balanced Binary Tree	0.509	简单
38	#776	Split BST	0.552	中等
39	#99	Recover Binary Search Tree	0.559	困难
40	#863	All Nodes Distance K in Binary Tree	0.477	中等
41	#103	Binary Tree Zigzag Level Order Traversal	0.54	中等
42	#563	Binary Tree Tilt	0.537	简单
43	#684	Redundant Connection	0.571	中等
44	#235	Lowest Common Ancestor of a Binary Search Tree	0.629	简单
45	#515	Find Largest Value in Each Tree Row	0.585	中等
46	#297	Serialize and Deserialize Binary Tree	0.458	困难
47	#236	Lowest Common Ancestor of a Binary Tree	0.608	中等
48	#513	Find Bottom Left Tree Value	0.688	中等
49	#606	Construct String from Binary Tree	0.527	简单
50	#652	Find Duplicate Subtrees	0.527	中等
51	#113	Path Sum II	0.589	中等
52	#106	Construct Binary Tree from Inorder and Postorder Traversal	0.675	中等
53	#508	Most Frequent Subtree Sum	0.627	中等
54	#230	Kth Smallest Element in a BST	0.694	中等
55	#129	Sum Root to Leaf Numbers	0.624	中等
56	#662	Maximum Width of Binary Tree	0.358	中等
57	#783	Minimum Distance Between BST Nodes	0.52	简单
58	#98	Validate Binary Search Tree	0.295	中等
59	#572	Subtree of Another Tree	0.439	简单
60	#671	Second Minimum Node In a Binary Tree	0.459	简单
61	#450	Delete Node in a BST	0.392	中等
62	#250	Count Univalue Subtrees	0.619	中等
63	#685	Redundant Connection II	0.335	困难
64	#623	Add One Row to Tree	0.505	中等
65	#116	Populating Next Right Pointers in Each Node	0.564	中等
66	#998	Maximum Binary Tree II	0.593	中等
67	#255	Verify Preorder Sequence in Binary Search Tree	0.458	中等
68	#333	Largest BST Subtree	0.421	中等
69	#1008	Construct Binary Search Tree from Preorder Traversal	0.717	中等
70	#117	Populating Next Right Pointers in Each Node II	0.464	中等
71	#988	Smallest String Starting From Leaf	0.442	中等
72	#270	Closest Binary Search Tree Value	0.506	简单
73	#549	Binary Tree Longest Consecutive Sequence II	0.473	中等
74	#582	Kill Process	0.346	中等
75	#156	Binary Tree Upside Down	0.73	中等
76	#285	Inorder Successor in BST	0.607	中等
77	#272	Closest Binary Search Tree Value II	0.587	困难
78	#666	Path Sum IV	0.585	中等
79	#366	Find Leaves of Binary Tree	0.73	中等
80	#536	Construct Binary Tree from String	0.513	中等
81	#545	Boundary of Binary Tree	0.349	中等
82	#298	Binary Tree Longest Consecutive Sequence	0.54	中等

相关/参考链接

leetcode-cn
leetcode