Leetcode刷题指南和top100题目

原文链接：https://blog.csdn.net/qq_39521554/article/details/79160815
参考博文：https://blog.csdn.net/mmc2015/article/details/87200435

一、刷题方法

方法一：按照题目出现频率刷题

顺序参考文章最后的部分

方法二：标签法
按照网站给大家排列的不同tags，起到模块化的复习和学习作用。举个例子：比如复习链表的内容，就选Linked List这部分的23个题目。刷完之后可以再总结一下常用的方法和数据结构与构造方式。请不要为了刷题而刷题，一定是为了弥补一部分的知识去做。

方法三：随机法
随心所欲的选择难度与刷题顺序，哪个顺眼做哪个。本方法只适合业余编程，不从事本行业的同学以及大神级人物

方法四：必杀法
leetcode是有公司题库的，一句话：面哪家，刷哪家

 

方法五：顺序法
建议未刷过题的新人按着顺序（AC）来。前 150 题覆盖了很多经典题目和知识点，指针法类如『3 sum』系列，动规类如『regex matching』，搜索类题目如『Sodoku Solver』。

基本熟悉知识点（图、树、堆、栈、链表、哈希表、记忆搜索、动态规划、指针法、并查集等）后，可以一类类标签强攻。Leetcode 右侧的标签系统虽然未必 100% 完整，但是大致分类做得还不错。

面试前的一个月可以只做『Hard』标签的题目，因为一般两遍之后对于大部分『Medium』难度以下的题目都是肌肉记忆了。多练习『Hard』类题目可以让自己的思路更开阔，因为很多题目使用的奇淫巧技让人惊讶，比如 Leetcode 精心设计连续题号的『84. Largest Rectangle in Histogram』、『85. Maximal Rectangle』。

 

二、刷题攻略
TIP 1：

对于大多数人来说，没有时间也没有必要把所有题目都做一遍（时间充裕可以随意）。

可以考虑序号为前250位的题目，因为那些全是经典与必考题。

TIP 2：

善用收藏夹，要养成『一道题第二次练习尚不能解就加入收藏夹』的习惯，且需要定期清空收藏夹：每道题不需提示下通过两次后才能移出收藏夹。

TIP 3：

可以按照下文的面试出题频率顺序来做，从频率最高的一批开始。 而且请尽量不使用IDE，直接在平台上写代码。 

面试前可以购买会员，按照公司的标签来练习，也可以结合白板练习。面试前如果时间紧迫，那么练习的优先级分别是：即将面试公司的题目、收藏夹里的旧题目、剩余的新题。

冲刺阶段的练习请尽量不要打开题型标签，给自己思考的空间。如果真的刷了三遍以上还没法达到理想目标，那么一定是学习方法出了问题，请多总结。

TIP 4：
写好代码先不要提交，人工检查一下代码，比如分号是否都有写，return有没少等。 人工检查完后使用“Custom Testcase”功能自定义测试用例，注意检查边界，然后“Run Code”，这步可以发现蛮多问题的。  等RunCode通过后，再去提交。

 

 

————

Top 100个题目：https://leetcode.com/problemset/top-100-liked-questions/

---

	#	Title	Solution	Acceptance	Difficulty	Frequency
	1	Two Sum		40.2%	Easy
	2	Add Two Numbers		30.4%	Medium
	3	Longest Substring Without Repeating Characters		26.1%	Medium
	4	Median of Two Sorted Arrays		25.3%	Hard
	5	Longest Palindromic Substring		26.4%	Medium
	10	Regular Expression Matching		24.9%	Hard
	11	Container With Most Water		42.1%	Medium
	15	3Sum		23.2%	Medium
	17	Letter Combinations of a Phone Number		40.1%	Medium
	19	Remove Nth Node From End of List		33.9%	Medium
	20	Valid Parentheses		35.7%	Easy
	21	Merge Two Sorted Lists		45.5%	Easy
	22	Generate Parentheses		52.8%	Medium
	23	Merge k Sorted Lists		32.6%	Hard
	31	Next Permutation		30.0%	Medium
	32	Longest Valid Parentheses		24.8%	Hard
	33	Search in Rotated Sorted Array		32.6%	Medium
	34	Find First and Last Position of Element in Sorted Array		32.8%	Medium
	39	Combination Sum		46.3%	Medium
	42	Trapping Rain Water		41.5%	Hard
	46	Permutations		53.0%	Medium
	48	Rotate Image		46.4%	Medium
	49	Group Anagrams		44.3%	Medium
	53	Maximum Subarray		42.6%	Easy
	55	Jump Game		31.1%	Medium
	56	Merge Intervals		34.6%	Medium
	62	Unique Paths		46.1%	Medium
	64	Minimum Path Sum		45.2%	Medium
	70	Climbing Stairs		43.2%	Easy
	72	Edit Distance		36.2%	Hard
	75	Sort Colors		41.1%	Medium
	76	Minimum Window Substring		29.6%	Hard
	78	Subsets		50.5%	Medium
	79	Word Search		30.2%	Medium
	84	Largest Rectangle in Histogram		30.1%	Hard
	85	Maximal Rectangle		32.2%	Hard
	94	Binary Tree Inorder Traversal		54.7%	Medium
	96	Unique Binary Search Trees		44.8%	Medium
	98	Validate Binary Search Tree		25.1%	Medium
	101	Symmetric Tree		42.5%	Easy
	102	Binary Tree Level Order Traversal		46.7%	Medium
	104	Maximum Depth of Binary Tree		58.9%	Easy
	105	Construct Binary Tree from Preorder and Inorder Traversal		39.1%	Medium
	114	Flatten Binary Tree to Linked List		40.8%	Medium
	121	Best Time to Buy and Sell Stock		46.0%	Easy
	124	Binary Tree Maximum Path Sum		29.1%	Hard
	128	Longest Consecutive Sequence		40.7%	Hard
	136	Single Number		58.7%	Easy
	139	Word Break		34.1%	Medium
	141	Linked List Cycle		35.5%	Easy

	#	Title	Solution	Acceptance	Difficulty	Frequency
	142	Linked List Cycle II		30.7%	Medium
	146	LRU Cache		23.7%	Hard
	148	Sort List		33.6%	Medium
	152	Maximum Product Subarray		28.4%	Medium
	155	Min Stack		35.3%	Easy
	160	Intersection of Two Linked Lists		31.9%	Easy
	169	Majority Element		51.2%	Easy
	198	House Robber		40.7%	Easy
	200	Number of Islands		40.0%	Medium
	206	Reverse Linked List		52.3%	Easy
	207	Course Schedule		36.4%	Medium
	208	Implement Trie (Prefix Tree)		36.4%	Medium
	215	Kth Largest Element in an Array		45.5%	Medium
	221	Maximal Square		32.1%	Medium
	226	Invert Binary Tree		56.8%	Easy
	234	Palindrome Linked List		35.2%	Easy
	236	Lowest Common Ancestor of a Binary Tree		35.0%	Medium
	238	Product of Array Except Self		53.6%	Medium
	239	Sliding Window Maximum		36.8%	Hard
	240	Search a 2D Matrix II		40.1%	Medium
	253	Meeting Rooms II		41.9%	Medium
	279	Perfect Squares		40.4%	Medium
	283	Move Zeroes		53.4%	Easy
	287	Find the Duplicate Number		48.0%	Medium
	297	Serialize and Deserialize Binary Tree		39.0%	Hard
	300	Longest Increasing Subsequence		40.1%	Medium
	301	Remove Invalid Parentheses		38.2%	Hard
	309	Best Time to Buy and Sell Stock with Cooldown		43.4%	Medium
	312	Burst Balloons		46.0%	Hard
	322	Coin Change		28.8%	Medium
	337	House Robber III		47.1%	Medium
	338	Counting Bits		63.8%	Medium
	347	Top K Frequent Elements		53.1%	Medium
	394	Decode String		43.6%	Medium
	406	Queue Reconstruction by Height		58.7%	Medium
	416	Partition Equal Subset Sum		39.7%	Medium
	437	Path Sum III		41.8%	Easy
	438	Find All Anagrams in a String		36.1%	Easy
	448	Find All Numbers Disappeared in an Array		52.6%	Easy
	461	Hamming Distance		70.0%	Easy
	494	Target Sum		44.8%	Medium
	538	Convert BST to Greater Tree		49.8%	Easy
	543	Diameter of Binary Tree		46.1%	Easy
	560	Subarray Sum Equals K		41.5%	Medium
	572	Subtree of Another Tree		41.1%	Easy
	581	Shortest Unsorted Continuous Subarray		29.6%	Easy
	617	Merge Two Binary Trees		69.0%	Easy
	621	Task Scheduler		44.1%	Medium
	647	Palindromic Substrings		55.5%	Medium
	771	Jewels and Stones		82.6%	Easy

 

 

 

 

出现频度为5： 
1. Leet Code OJ 1. Two Sum [Difficulty: Easy] 
2. Leet Code OJ 8. String to Integer (atoi) [Difficulty: Easy] 
3. Leet Code OJ 15. 3Sum [Difficulty: Medium] 
4. Leet Code OJ 20. Valid Parentheses [Difficulty: Easy] 
5. Leet Code OJ 21. Merge Two Sorted Lists [Difficulty: Easy] 
6. Leet Code OJ 28. Implement strStr() [Difficulty: Easy] 
7. Leet Code OJ 56. Merge Intervals [Difficulty: Hard] 
8. Leet Code OJ 57. Insert Interval [Difficulty: Hard] 
9. Leet Code OJ 65. Valid Number [Difficulty: Hard] 
10. Leet Code OJ 70. Climbing Stairs [Difficulty: Easy] 
11. Leet Code OJ 73. Set Matrix Zeroes [Difficulty: Medium] 
12. Leet Code OJ 88. Merge Sorted Array [Difficulty: Easy] 
13. Leet Code OJ 98. Validate Binary Search Tree [Difficulty: Medium] 
14. Leet Code OJ 125. Valid Palindrome [Difficulty: Easy] 
15. Leet Code OJ 127. Word Ladder [Difficulty: Medium]

出现频度为4： 
1. Leet Code OJ 2. Add Two Numbers [Difficulty: Medium] 
2. Leet Code OJ 12. Integer to Roman 
3. Leet Code OJ 13. Roman to Integer 
4. Leet Code OJ 22. Generate Parentheses 
5. Leet Code OJ 23. Merge k Sorted Lists 
6. Leet Code OJ 24. Swap Nodes in Pairs 
7. Leet Code OJ 27. Remove Element [Difficulty: Easy] 
8. Leet Code OJ 46. Permutations 
9. Leet Code OJ 49. Anagrams 
10. Leet Code OJ 67. Add Binary 
11. Leet Code OJ 69. Sqrt(x) 
12. Leet Code OJ 77. Combinations 
13. Leet Code OJ 78. Subsets 
14. Leet Code OJ 79. Word Search 
15. Leet Code OJ 91. Decode Ways [Difficulty: Medium] 
16. Leet Code OJ 102. Binary Tree Level Order Traversal [Difficulty: Easy] 
17. Leet Code OJ 129. Sum Root to Leaf Numbers 
18. Leet Code OJ 131. Palindrome Partitioning

相关资源推荐

LeetCode和剑指offer题目大合集

关于LeetCode刷题及题目列表归纳