作者： 负雪明烛
id： fuxuemingzhu
个人博客： http://fuxuemingzhu.cn/

把自己刷过的所有题目做一个整理，并且用简洁的语言概括了一下思路，汇总成了一个表格。

题目的排列顺序是按照先Easy再Medium再Hard排列的，暂时还没有把题目全部整理完成。后序我会把刷过的所有的题目都整理到这个文档里。

题目 难度 解法 题目地址
566. Reshape the Matrix Easy 变长数组，求余法，维护行列计算在新的数组中的位置 https://blog.csdn.net/fuxuemingzhu/article/details/83626519
897. Increasing Order Search Tree Easy 直接中序遍历的结果放到链表结尾 https://blog.csdn.net/fuxuemingzhu/article/details/82349263
771. Jewels and Stones Easy 字典统计次数 https://blog.csdn.net/fuxuemingzhu/article/details/79188903
929. Unique Email Addresses Easy 字符串+set统计个数 https://blog.csdn.net/fuxuemingzhu/article/details/83478570
709. To Lower Case Easy ASIIC码操作ord,chr https://blog.csdn.net/fuxuemingzhu/article/details/81015228
804. Unique Morse Code Words Easy 字典映射 + set统计个数 https://blog.csdn.net/fuxuemingzhu/article/details/79774003
905. Sort Array By Parity Easy 自定义sorted函数的cmp为数字mod 2 https://blog.csdn.net/fuxuemingzhu/article/details/82732066
461. Hamming Distance Easy 先异或 再数1的个数 https://blog.csdn.net/fuxuemingzhu/article/details/54138423
657. Robot Return to Origin Easy Counter统计，判断是否相等 https://blog.csdn.net/fuxuemingzhu/article/details/83663650
832. Flipping an Image Easy 直接计算新的数组的每个位置的值即可 https://blog.csdn.net/fuxuemingzhu/article/details/80471495
617. Merge Two Binary Trees Easy 树的递归操作 https://blog.csdn.net/fuxuemingzhu/article/details/79052953
28. Implement strStr() Easy 字符串遍历+切片是否相等的判断 https://blog.csdn.net/fuxuemingzhu/article/details/79254558
890. Find and Replace Pattern Easy 直接使用字典做映射 https://blog.csdn.net/fuxuemingzhu/article/details/82014687
814. Binary Tree Pruning Medium 二叉树的后序遍历 https://blog.csdn.net/fuxuemingzhu/article/details/79858752
561. Array Partition I Easy 排序+求和 https://blog.csdn.net/fuxuemingzhu/article/details/71412574
728. Self Dividing Numbers Easy 直接遍历区间的每个数字进行判断 https://blog.csdn.net/fuxuemingzhu/article/details/79053113
852. Peak Index in a Mountain Array Easy 二分查找的变种，使用Mid位置和左右位置比较 https://blog.csdn.net/fuxuemingzhu/article/details/80721162
922. Sort Array By Parity II Easy 分别求出奇偶数组然后拼接 https://blog.csdn.net/fuxuemingzhu/article/details/83045735
883. Projection Area of 3D Shapes Easy 分别计算三视图的面积即可 https://blog.csdn.net/fuxuemingzhu/article/details/81748335
908. Smallest Range I Easy 直接数学计算 https://blog.csdn.net/fuxuemingzhu/article/details/82824685
867. Transpose Matrix Easy 先构建数组再遍历实现翻转 https://blog.csdn.net/fuxuemingzhu/article/details/81015450
589. N-ary Tree Preorder Traversal Easy 多叉树的先序遍历，可以用递归和迭代 https://blog.csdn.net/fuxuemingzhu/article/details/81021950
590. N-ary Tree Postorder Traversal Easy 多叉树的后序遍历 https://blog.csdn.net/fuxuemingzhu/article/details/81017965
350. Intersection of Two Arrays II Easy 先排序然后用两个指针移动找出数组交集 https://blog.csdn.net/fuxuemingzhu/article/details/54341965
876. Middle of the ed List Easy 快慢指针同时向链表后面移动 https://blog.csdn.net/fuxuemingzhu/article/details/81748484
700. Search in a Binary Search Tree Easy BST中节点的查找，递归 https://blog.csdn.net/fuxuemingzhu/article/details/81015754
933. Number of Recent Calls Easy 找出满足一定条件的区间长度，可以使用二分或者队列 https://blog.csdn.net/fuxuemingzhu/article/details/83714891
559. Maximum Depth of N-ary Tree Easy 求树的高度，可以使用BFS和DFS https://blog.csdn.net/fuxuemingzhu/article/details/81021864
557. Reverse Words in a String III Easy 字符串的单词分别翻转再拼接到一起就好了 https://blog.csdn.net/fuxuemingzhu/article/details/70141268
806. Number of Lines To Write String Easy 使用字典保存每个字符的长度，然后统计每行的长度是否超过100就好了 https://blog.csdn.net/fuxuemingzhu/article/details/79810381
344. Reverse String Easy 字符串翻转，[::-1 https://blog.csdn.net/fuxuemingzhu/article/details/51284382
811. Subdomain Visit Count Easy 字典保存每个子域名出现的次数即可 https://blog.csdn.net/fuxuemingzhu/article/details/79789925
476. Number Complement Easy 求数字的补数，方法是异或上与其二进制数字的长度相等的全1二进制数 https://blog.csdn.net/fuxuemingzhu/article/details/54562124
821. Shortest Distance to a Character Easy 过两遍数组，分别找出距离左边和右边的这个字符的最短距离 https://blog.csdn.net/fuxuemingzhu/article/details/80471765
500. Keyboard Row Easy 使用字典保存每行元素，然后看每个单词是不是只由一行元素组成 https://blog.csdn.net/fuxuemingzhu/article/details/68953517
893. Groups of Special-Equivalent Strings Easy 把奇偶位置都取出来，重新拼接成字符串作为指纹，看总的有多少种指纹 https://blog.csdn.net/fuxuemingzhu/article/details/82083609
872. Leaf-Similar Trees Easy 先序、中序、后序都能得到叶子序列 https://blog.csdn.net/fuxuemingzhu/article/details/81748617
884. Uncommon Words from Two Sentences Easy 使用字典统计每个单词出现的次数，然后看字典keys()的交集，然后在字典中看是不是只出现了一次 https://blog.csdn.net/fuxuemingzhu/article/details/81749170
766. Toeplitz Matrix Easy 判断每个斜线是否相等，方法是判断每个元素是否和其左上角元素相等 https://blog.csdn.net/fuxuemingzhu/article/details/79127213
463. Island Perimeter Easy 求小岛的周长。使用所有陆地个数×4-相交部分×2. https://blog.csdn.net/fuxuemingzhu/article/details/83868905
682. ball Game Easy 用一个栈进行模拟 https://blog.csdn.net/fuxuemingzhu/article/details/79183412
868. Binary Gap Easy 二进制表示中1的最大间距，保留上一个1的位置即可 https://blog.csdn.net/fuxuemingzhu/article/details/81079495
104. Maximum Depth of Binary Tree Easy 二叉树的高度，可以用DFS和BFS https://blog.csdn.net/fuxuemingzhu/article/details/48490829
136. Single Number Easy 所有的数字出现了两次，其中一个只出现了一次。找出这个数字的方法可以使用字典统计或者异或运算 https://blog.csdn.net/fuxuemingzhu/article/details/54173334
496. Next Greater Element I Easy 找出某个数字右边比他大的数字，直接遍历查找就好了 https://blog.csdn.net/fuxuemingzhu/article/details/79080337
637. Average of Levels in Binary Tree Easy 求每层的二叉树的均值，可以使用BFS和DFS https://blog.csdn.net/fuxuemingzhu/article/details/79088554
693. Binary Number with Alternating Bits Easy 判断数字的二进制表示是不是01交错的。直接遍历判断，或者位运算。 https://blog.csdn.net/fuxuemingzhu/article/details/79089937
762. Prime Number of Set Bits in Binary Representation Easy 判断二进制数字的1的个数是不是质数 https://blog.csdn.net/fuxuemingzhu/article/details/79089092
917. Reverse Only Letters Easy 只翻转字母其余字符不动，可以使用栈、双指针 https://blog.csdn.net/fuxuemingzhu/article/details/82956271
292. Nim Game Easy 判断输入数字是不是4的倍数即可 https://blog.csdn.net/fuxuemingzhu/article/details/51284421
824. Goat Latin Easy 字符串处理，简单 https://blog.csdn.net/fuxuemingzhu/article/details/80471925
892. Surface Area of 3D Shapes Easy 统计立方体个数，减去相交面积 https://blog.csdn.net/fuxuemingzhu/article/details/82083893
784. Letter Case Permutation Easy 经典回溯法，把字符的大小写分别拼接到字符串尾部 https://blog.csdn.net/fuxuemingzhu/article/details/79360330
258. Add Digits Easy 两重循环，一直对每位数字求和直到剩余个位数 https://blog.csdn.net/fuxuemingzhu/article/details/49161129
283. Move Zeroes Easy 使用一个指针指向第一个为0的位置，然后遍历不是0的位置进行交换 https://blog.csdn.net/fuxuemingzhu/article/details/51284981
748. Shortest Completing Word Easy 找出符合某个模式的字符串，直接处理就好了 https://blog.csdn.net/fuxuemingzhu/article/details/79432228
690. Employee Importance Easy dfs https://blog.csdn.net/fuxuemingzhu/article/details/79091343
389. Find the Difference Easy 找多出来的字符，可以使用字典，也可以使用异或 https://blog.csdn.net/fuxuemingzhu/article/details/54174443
520. Detect Capital Easy 统计大写字符的个数，判断是不是在首位 https://blog.csdn.net/fuxuemingzhu/article/details/68957658
448. Find All Numbers Disappeared in an Array Easy 用set去重，找出没有出现的数字即可 https://blog.csdn.net/fuxuemingzhu/article/details/53981307
696. Count Binary Substrings Easy 先找出连续的0，1个数，然后进行交错求最小值，在求和 https://blog.csdn.net/fuxuemingzhu/article/details/79183556
454. 4Sum II Easy 4sum，先确定两个数字，然后看剩余两个数字的和是否出现过 https://blog.csdn.net/fuxuemingzhu/article/details/79473739
788. Rotated Digits Easy 字典保存翻转后的数字，判断是否相等即可。 https://blog.csdn.net/fuxuemingzhu/article/details/79378135
653. Two Sum IV - Input is a BST Easy BFS或者DFS，在遍历的过程中进行破案吨 https://blog.csdn.net/fuxuemingzhu/article/details/79120732
371. Sum of Two Integers Easy 位运算 https://blog.csdn.net/fuxuemingzhu/article/details/79379939
349. Intersection of Two Arrays Easy 用两个set求交集，然后转成List即可 https://blog.csdn.net/fuxuemingzhu/article/details/54236183
606. Construct String from Binary Tree Easy 先序遍历，可以省略右子树，所以需要做一个节点是否存在的判断 https://blog.csdn.net/fuxuemingzhu/article/details/79121550
206. Reverse ed List Easy 翻转单链表，可以使用递归和迭代 https://blog.csdn.net/fuxuemingzhu/article/details/51290121
169. Majority Element Easy Moore投票法，或者字典统计次数 https://blog.csdn.net/fuxuemingzhu/article/details/51288749
171. Excel Sheet Column Number Easy 26进制，没有难度 https://blog.csdn.net/fuxuemingzhu/article/details/51286467
13. Roman to Integer Easy 使用字典保存映射，遍历求值就好了。 https://blog.csdn.net/fuxuemingzhu/article/details/48208995
937. Reorder Log Files Easy 分割排序，再拼接 https://blog.csdn.net/fuxuemingzhu/article/details/83961188
121. Best Time to Buy and Sell Stock Easy 一次遍历，如果后一天比前一天大就买了卖 https://blog.csdn.net/fuxuemingzhu/article/details/51291151
242. Valid Anagram Easy 判断字符串是否是同构的，直接统计词频或者排序 https://blog.csdn.net/fuxuemingzhu/article/details/51286195
860. Lemonade Change Easy 贪心算法，找零钱先找大的面额，如果不够再用小的面额 https://blog.csdn.net/fuxuemingzhu/article/details/80913955
217. Contains Duplicate Easy 判断数组是否有重复，可以统计词频，判断set长度是否相等，排序等方法 https://blog.csdn.net/fuxuemingzhu/article/details/51289768
427. Construct Quad Tree Easy 建立四叉树，使用递归，判断4个叶子全部是0或者1 https://blog.csdn.net/fuxuemingzhu/article/details/81836838
706. Design HashMap Easy 设计一个字典，直接开个很大的数组即可，内存放得下 https://blog.csdn.net/fuxuemingzhu/article/details/81017297
538. Convert BST to Greater Tree Easy 把每个节点变成比它大的节点的值的和，采用逆中序遍历。 https://blog.csdn.net/fuxuemingzhu/article/details/79132336
100. Same Tree Easy 判断两棵数是否相等，直接递归 https://blog.csdn.net/fuxuemingzhu/article/details/51285076
530. Minimum Absolute Difference in BST Easy 中序遍历，保存前一个节点，当前节点的值减去前一个节点的值 https://blog.csdn.net/fuxuemingzhu/article/details/69666671
783. Minimum Distance Between BST Nodes Easy 和上题完全一样 https://blog.csdn.net/fuxuemingzhu/article/details/79402127
383. Ransom Note Easy 使用字典统计每个字符出现的次数，前者小于后者即可 https://blog.csdn.net/fuxuemingzhu/article/details/54178342
796. Rotate String Easy 字符串切片 https://blog.csdn.net/fuxuemingzhu/article/details/79521194
717. 1-bit and 2-bit Characters Easy 单次遍历，判断前面满足的条件下，最后一位是0即可。 https://blog.csdn.net/fuxuemingzhu/article/details/79130681
453. Minimum Moves to Equal Array Elements Easy 把n-1个数字加1，相等于把最大值-1.求和-n*最小值 https://blog.csdn.net/fuxuemingzhu/article/details/54177981
733. Flood Fill Easy 对相同颜色进行染色，可以使用DFS和BFS. https://blog.csdn.net/fuxuemingzhu/article/details/79401716
404. Sum of Left Leaves Easy 求所有左叶子的和，要判断是不是在左边，判断是不是叶子，然后加到结果中 https://blog.csdn.net/fuxuemingzhu/article/details/54178595
447. Number of Boomerangs Easy 统计回旋镖的个数，不能暴力解决，需要使用排列组合公式n*(n-1) https://blog.csdn.net/fuxuemingzhu/article/details/54379349
598. Range Addition II Easy 求队列的最小值即可 https://blog.csdn.net/fuxuemingzhu/article/details/79398272
492. Construct the Rectangle Easy 从算术平方根开始找约数即可 https://blog.csdn.net/fuxuemingzhu/article/details/68957959
167. Two Sum II - Input array is sorted Easy 前后指针同时向中间走，找到target之后停止 https://blog.csdn.net/fuxuemingzhu/article/details/70232518
387. First Unique Character in a String Easy 首先做个字符出现次数的统计，然后再次遍历，找出只出现了一次的第一个字符。 https://blog.csdn.net/fuxuemingzhu/article/details/84139374
697. Degree of an Array Easy 求最大的出现次数的所有数字，其最左右出现的位置差的最小值 https://blog.csdn.net/fuxuemingzhu/article/details/79146067
455. Assign Cookies Easy 贪心算法，尽可能给小孩满足其欲望的饼干 https://blog.csdn.net/fuxuemingzhu/article/details/54177627
108. Convert Sorted Array to Binary Search Tree Easy 构建BST，使用中间数进行分割，用递归 https://blog.csdn.net/fuxuemingzhu/article/details/70665213
506. Relative Ranks Easy 相对排名，可以使用堆或者排序或者argsort https://blog.csdn.net/fuxuemingzhu/article/details/70173434
661. Image Smoother Easy 直接暴力求平均即可 https://blog.csdn.net/fuxuemingzhu/article/details/79156499
409. Longest Palindrome Easy 统计出现次数的奇偶就可以 https://blog.csdn.net/fuxuemingzhu/article/details/54236594
599. Minimum Index Sum of Two Lists Easy 保存出现的索引和与元素的对应，使用堆保存最小的就行 https://blog.csdn.net/fuxuemingzhu/article/details/79138621
268. Missing Number Easy 理论和-当前和 https://blog.csdn.net/fuxuemingzhu/article/details/70332471
563. Binary Tree Tilt Easy 后序遍历函数返回的是左右子树的差，在里面用变量求和 https://blog.csdn.net/fuxuemingzhu/article/details/71440281
830. Positions of Large Groups Easy 找到长度大于3的连续字符，需要判断结束！！ https://blog.csdn.net/fuxuemingzhu/article/details/80472242
350. Intersection of Two Arrays II Easy 可以排序，也可以使用字典统计次数 https://blog.csdn.net/fuxuemingzhu/article/details/54341965
543. Diameter of Binary Tree Easy 递归求树的深度，同时求左右两个深度的和的最大值 https://blog.csdn.net/fuxuemingzhu/article/details/70338312
551. Student Attendance Record I Easy 统计A的个数，并且判断连续L的个数 https://blog.csdn.net/fuxuemingzhu/article/details/70337973
121. Best Time to Buy and Sell Stock Easy 保存当前的最小值以及最大收益即可 https://blog.csdn.net/fuxuemingzhu/article/details/51291151
628. Maximum Product of Three Numbers Easy 找出三个数最大的乘积 https://blog.csdn.net/fuxuemingzhu/article/details/79169635
401. Binary Watch Easy 使用combinations函数 https://blog.csdn.net/fuxuemingzhu/article/details/54344098
746. Min Cost Climbing Stairs Easy 动态规划 https://blog.csdn.net/fuxuemingzhu/article/details/79188612
925. Long Pressed Name Easy 使用双指针，统计连续字符出现的次数 https://blog.csdn.net/fuxuemingzhu/article/details/83245395
541. Reverse String II Easy Python的切片翻转 https://blog.csdn.net/fuxuemingzhu/article/details/70141909
705. Design HashSet Easy 直接开数组就行 https://blog.csdn.net/fuxuemingzhu/article/details/81016992
107. Binary Tree Level Order Traversal II Easy DFS和BFS都可以 https://blog.csdn.net/fuxuemingzhu/article/details/49108449
504. 7 Easy 转成7进制 https://blog.csdn.net/fuxuemingzhu/article/details/70194688
115. Distinct Subsequences Easy 动规，判断当前字符是否相等 https://blog.csdn.net/fuxuemingzhu/article/details/84228383
21. Merge Two Sorted Lists Easy 可以使用递归或者迭代 https://blog.csdn.net/fuxuemingzhu/article/details/51291406
458. Poor Pigs Easy 类似拨号键盘，多维空间求解 https://blog.csdn.net/fuxuemingzhu/article/details/81079261
257. Binary Tree Paths Easy 打印二叉树的路径，使用递归和迭代 https://blog.csdn.net/fuxuemingzhu/article/details/71249429
844. Backspace String Compare Easy 字符串可以退格，使用栈轻松解决 https://blog.csdn.net/fuxuemingzhu/article/details/80643408
202. Happy Number Easy 递归和迭代两种做法 https://blog.csdn.net/fuxuemingzhu/article/details/49180507
674. Longest Continuous Increasing Subsequence Easy 简单的动态规划 https://blog.csdn.net/fuxuemingzhu/article/details/79220527
744. Find Smallest Letter Greater Than Target Easy 线性扫描或者二分 https://blog.csdn.net/fuxuemingzhu/article/details/79137225
118. Pascal’s Triangle Easy 提前构造出来，然后处理每行即可 https://blog.csdn.net/fuxuemingzhu/article/details/51346488
671. Second Minimum Node In a Binary Tree Easy 递归的时候找第二小值 https://blog.csdn.net/fuxuemingzhu/article/details/79222455
720. Longest Word in Dictionary Easy 先排序，再找前缀是否存在。 https://blog.csdn.net/fuxuemingzhu/article/details/79123277
27. Remove Element Easy 使用双指针或者标记指针使得前面都是满足要求的，后面都不满足 https://blog.csdn.net/fuxuemingzhu/article/details/51303161
70. Climbing Stairs Easy 动态规划 https://blog.csdn.net/fuxuemingzhu/article/details/51290778
415. Add Strings Easy 直接模拟大整数加法，需要注意进位问题 https://blog.csdn.net/fuxuemingzhu/article/details/54380737
235. Lowest Common Ancestor of a Binary Search Tree Easy BST找公共祖先，使用递归很简单 https://blog.csdn.net/fuxuemingzhu/article/details/51290289
594. Longest Harmonious Subsequence Easy 统计相邻的数字是否都存在即可 https://blog.csdn.net/fuxuemingzhu/article/details/79233752
101. Symmetric Tree Easy 可以使用BFS和DFS两种方法 https://blog.csdn.net/fuxuemingzhu/article/details/51345707
53. Maximum Subarray Easy 动态规划找子数组最大和 https://blog.csdn.net/fuxuemingzhu/article/details/71101802
819. Most Common Word Easy 正则+统计 https://blog.csdn.net/fuxuemingzhu/article/details/80472079
231. Power of Two Easy 判断二进制是不是只有1个1即可 https://blog.csdn.net/fuxuemingzhu/article/details/51290981
405. Convert a Number to Hexadecimal Easy 转成16进制，难点在于负数的处理：加上1<<32 https://blog.csdn.net/fuxuemingzhu/article/details/54426643
83. Remove Duplicates from Sorted List Easy 递归和循环 https://blog.csdn.net/fuxuemingzhu/article/details/51290506
326. Power of Three Easy 循环和迭代 https://blog.csdn.net/fuxuemingzhu/article/details/51290895
191. Number of 1 Bits Easy 使用位移统计二进制个数 https://blog.csdn.net/fuxuemingzhu/article/details/51290376
437. Path Sum III Easy 找路径的个数，使用DFS*2或者BFS+DFS https://blog.csdn.net/fuxuemingzhu/article/details/71097135
704. Binary Search Easy 二分的模板 https://blog.csdn.net/fuxuemingzhu/article/details/81017415
119. Pascal’s Triangle II Easy 原地翻转可以用倒序遍历 https://blog.csdn.net/fuxuemingzhu/article/details/51348629
232. Implement Queue using Stacks Easy 两个栈实现一个队列 https://blog.csdn.net/fuxuemingzhu/article/details/51345762
572. Subtree of Another Tree Easy DFS*2或DFS+BSF https://blog.csdn.net/fuxuemingzhu/article/details/71440802
198. House Robber Easy 简单dp，当前房间偷和不偷两种状态 https://blog.csdn.net/fuxuemingzhu/article/details/51291936
703. Kth Largest Element in a Stream Easy 使用小根堆维护k个值，则第一个元素就是第k大元素 https://blog.csdn.net/fuxuemingzhu/article/details/81027116
345. Reverse Vowels of a String Easy 使用栈进行翻转，或者使用双指针 https://blog.csdn.net/fuxuemingzhu/article/details/51291677
66. Plus One Easy 使用carry表示进位 https://blog.csdn.net/fuxuemingzhu/article/details/51346096
263. Ugly Number Easy 除去2,3,5因子即可 https://blog.csdn.net/fuxuemingzhu/article/details/49183961
35. Search Insert Position Easy 二分查找 https://blog.csdn.net/fuxuemingzhu/article/details/70738108
645. Set Mismatch Easy 使用统计次数或者直接求和计算 https://blog.csdn.net/fuxuemingzhu/article/details/79247916
747. Largest Number At Least Twice of Others Easy 找出最大值，然后弹掉，再找次大值即可。 https://blog.csdn.net/fuxuemingzhu/article/details/79188909
342. Power of Four Easy 递归和迭代 https://blog.csdn.net/fuxuemingzhu/article/details/51291091
724. Find Pivot Index Easy 先求和，在遍历求前半部分的和，找出左边等于右边 https://blog.csdn.net/fuxuemingzhu/article/details/79248308
9. Palindrome Number Easy 可以先翻转成整数，然后判断和原来的是否相等 https://blog.csdn.net/fuxuemingzhu/article/details/71334663
482. License Key Formatting Easy 计算第一个分割的长度，后面都是等长的了 https://blog.csdn.net/fuxuemingzhu/article/details/79234075
1. Two Sum Easy 保存已经出现过的数字的索引，当下次遍历的时候遇到了满足要求的结果，那么既是停止 https://blog.csdn.net/fuxuemingzhu/article/details/72465759
459. Repeated Substring Pattern Easy 判断每个子串重复多次能不能组成原来的串即可 https://blog.csdn.net/fuxuemingzhu/article/details/54564801
849. Maximize Distance to Closest Person Easy 从前向后以及从后向前遍历两次，取最近距离 https://blog.csdn.net/fuxuemingzhu/article/details/80643250
38. Count and Say Easy 统计字符连续出现的次数，并说出来，需要注意最后的一个字符也要添加上去 https://blog.csdn.net/fuxuemingzhu/article/details/71618640
80. Remove Duplicates from Sorted Array II Easy 快指针移动判断和慢指针是否相等，如果不等就换到前面来 https://blog.csdn.net/fuxuemingzhu/article/details/82829709
643. Maximum Average Subarray I Easy 一定注意是长度为k的滑动窗口，注意下标 https://blog.csdn.net/fuxuemingzhu/article/details/79248629
501. Find Mode in Binary Search Tree Easy 如果使用附加空间，可以使用字典保存次数；否则需要遍历两次，判断出现次数。 https://blog.csdn.net/fuxuemingzhu/article/details/71124600
374. Guess Number Higher or Lower Easy 使用二分查找 https://blog.csdn.net/fuxuemingzhu/article/details/71516105
743. Network Delay Time Easy dijkstra算法 https://leetcode.com/problems/network-delay-time/de ion/
558. Quad Tree Intersection Easy 递归构造 https://blog.csdn.net/fuxuemingzhu/article/details/82356008
172. Factorial Trailing Zeroes Easy 数有多少个5就行了 https://blog.csdn.net/fuxuemingzhu/article/details/51347044
441. Arranging Coins Easy 二分查找满足条件的层数即可 https://blog.csdn.net/fuxuemingzhu/article/details/71330733
225. Implement Stack using Queues Easy 使用一个队列就能实现栈，每次Push的时候，把队列里的所有元素弹出再放进来就好了。 https://blog.csdn.net/fuxuemingzhu/article/details/72598111
67. Add Binary Easy 使用进位进行模拟 ddhttps://blog.csdn.net/fuxuemingzhu/article/details/77341154v
434. Number of Segments in a String Easy string.split()默认就是按照多个空格分割 https://blog.csdn.net/fuxuemingzhu/article/details/71194298
112. Path Sum Easy 递归和迭代都能满足 https://blog.csdn.net/fuxuemingzhu/article/details/71715810
205. Isomorphic Strings Easy 分别看s到t的映射和t到s的映射是不是一一映射的 https://blog.csdn.net/fuxuemingzhu/article/details/72127108
443. String Compression Easy 使用Pos变量维护应该放到哪个位置，然后一次遍历统计次数就好了 https://blog.csdn.net/fuxuemingzhu/article/details/79183289
303. Range Sum Query - Immutable Easy 保存每个位置的累积和 https://blog.csdn.net/fuxuemingzhu/article/details/79253036
438. Find All Anagrams in a String Easy 滑动窗口，保存等长的子字符串中包含的字符数是否和另外一个相等 https://blog.csdn.net/fuxuemingzhu/article/details/79184109
20. Valid Parentheses Easy 使用栈判断括号是否合法 https://blog.csdn.net/fuxuemingzhu/article/details/72366868
840. Magic Squares In Grid Easy 暴力判断每个9*9的格子是不是满足题意的河图 https://blog.csdn.net/fuxuemingzhu/article/details/80473253
141. ed List Cycle Easy 走两步走一步，看是否重合 https://blog.csdn.net/fuxuemingzhu/article/details/51297249
203. Remove ed List Elements Easy 递归解法不好想，但是代码很简单 https://blog.csdn.net/fuxuemingzhu/article/details/77340945
234. Palindrome ed List Easy 利用一个数组保存所有的数字，然后判断数组是不是回文的。 https://blog.csdn.net/fuxuemingzhu/article/details/72597942
111. Minimum Depth of Binary Tree Easy DFS/BFS，其实DFS更难 https://blog.csdn.net/fuxuemingzhu/article/details/48519035
290. Word Pattern Easy 一一映射 https://blog.csdn.net/fuxuemingzhu/article/details/72528424
155. Min Stack Easy 使用辅助栈保存最小值 https://blog.csdn.net/fuxuemingzhu/article/details/79253237
219. Contains Duplicate II Easy 使用字典保存出现的位置，当新的元素到来的时候，更新字典 https://blog.csdn.net/fuxuemingzhu/article/details/77387169
941. Valid Mountain Array Easy 两个while就可以了 https://blog.csdn.net/fuxuemingzhu/article/details/84206380
88. Merge Sorted Array Easy 从后向前进行遍历，每次找到大的往后移动 https://blog.csdn.net/fuxuemingzhu/article/details/77444695
914. X of a Kind in a Deck of Cards Easy 需要进行一个遍历，找到是否存在这个分组大小 https://blog.csdn.net/fuxuemingzhu/article/details/82914279
680. Valid Palindrome II Easy 需要用到双指针，先找到第一个不相等的位置，然后去除左边或者右边，判断是否是回文 https://blog.csdn.net/fuxuemingzhu/article/details/79252779
687. Longest Univalue Path Easy 定义的DFS是对过root的单臂进行循环，但是更新的结果是双臂，有点意思 https://blog.csdn.net/fuxuemingzhu/article/details/79248926
14. Longest Common Prefix Easy 遍历最短的子串的每一位，看所有字符串在这一位上是不是相等的 https://blog.csdn.net/fuxuemingzhu/article/details/77561186
686. Repeated String Match Easy 重复NB/NA + 3次，看b是不是在a里 https://blog.csdn.net/fuxuemingzhu/article/details/79574835
122.Best Time to Buy and Sell Stock II Easy 只要每天的比前面一天高，那么就买上并且卖掉即可 https://blog.csdn.net/fuxuemingzhu/article/details/70258549
28. Implement strStr() Easy 循环加切片 https://blog.csdn.net/fuxuemingzhu/article/details/79254558
475. Heaters Easy 找出最临近的距离 https://blog.csdn.net/fuxuemingzhu/article/details/79254295
754. Reach a Number Easy 数学题，非常不喜欢 https://blog.csdn.net/fuxuemingzhu/article/details/84556932
400. Nth Digit Easy 数学计算第多少位 https://blog.csdn.net/fuxuemingzhu/article/details/84559975
69. Sqrt(x) Easy 二分查找或者牛顿法 https://blog.csdn.net/fuxuemingzhu/article/details/79254648
581. Shortest Unsorted Continuous Subarray Easy 先排序，然后比较不等的位置 https://blog.csdn.net/fuxuemingzhu/article/details/79254454
190. Reverse Bits Easy 翻转二进制再转成整数 https://blog.csdn.net/fuxuemingzhu/article/details/79254344
125. Valid Palindrome Easy 过滤掉不是字母的字符，然后判断是不是回文即可 https://blog.csdn.net/fuxuemingzhu/article/details/79252936
874. Walking Robot Simulation Easy 模拟整个过程即可 https://blog.csdn.net/fuxuemingzhu/article/details/82356556
532. K-diff Pairs in an Array Easy 找绝对值出现等于k的次数，需要对k进行判断 https://blog.csdn.net/fuxuemingzhu/article/details/79255633
168. Excel Sheet Column Easy 需要对26取余，并且做个判断，因为0\\26对26取余的结果是一样的 https://blog.csdn.net/fuxuemingzhu/article/details/51286857
189. Rotate Array Easy 可以使用额外数组，也可使用递归原地翻转 https://blog.csdn.net/fuxuemingzhu/article/details/79258753
665. Non-decreasing Array Easy 找到变小的位置，然后和再前面的数字进行判断，看是应该修改当前的还是前面的 https://blog.csdn.net/fuxuemingzhu/article/details/79264475
707. Design ed List Easy 自己实现链表，挺复杂的。可以使用list进行模拟，方便很多。 https://blog.csdn.net/fuxuemingzhu/article/details/81026066
938. Range Sum of BST Medium 需要根据根节点的值进行判断，邮编和左边需不需要继续寻找 https://blog.csdn.net/fuxuemingzhu/article/details/83961263
807. Max Increase to Keep City Skyline Medium 分别找出行和咧的最大值，把每个位置增长到行列最大值的最小值 https://blog.csdn.net/fuxuemingzhu/article/details/79820383
535. Encode and Decode TinyURL Medium 使用字典完成映射 https://blog.csdn.net/fuxuemingzhu
654. Maximum Binary Tree Medium 找到最大值，然后数组切片 https://blog.csdn.net/fuxuemingzhu/article/details/79265180
701. Insert into a Binary Search Tree Medium 递归解法，直接对当前节点进行操作！ https://blog.csdn.net/fuxuemingzhu/article/details/82385503
890. Find and Replace Pattern Medium 判断是不是一一映射 https://blog.csdn.net/fuxuemingzhu/article/details/82014687
921. Minimum Add to Make Parentheses Valid Medium 使用一个栈 https://blog.csdn.net/fuxuemingzhu/article/details/83045871
797. All Paths From Source to Target Medium 回溯法找路径 https://blog.csdn.net/fuxuemingzhu/article/details/79624149
861. Score After Flipping Matrix Medium 把行进行翻转，按列统计1的个数即可 https://blog.csdn.net/fuxuemingzhu/article/details/81118328
894. All Possible Full Binary Trees Medium 使用两种循环遍历可能构成的左子树和右子树，每次构建新的root https://blog.csdn.net/fuxuemingzhu/article/details/82084204
763. Partition Labels Medium 使用字典保存每个字符最后出现的位置，如果一个区间内字符的最后位置的都在一起，那么就添加到结果里 https://blog.csdn.net/fuxuemingzhu/article/details/79265829
419. Battleships in a Board Medium 直接数有多少小岛就行，判断小岛可以使用它的最左上角元素即可 https://blog.csdn.net/fuxuemingzhu/article/details/79403172
537. Complex Number Multiplication Medium 复数运算，重点是分割字符串 https://blog.csdn.net/fuxuemingzhu/article/details/79266080
338. Counting Bits Medium i的二进制1个数等于i/2的二进制个数+i%2 https://blog.csdn.net/fuxuemingzhu/article/details/70806676
885. Spiral Matrix III Medium 保留循环更新步数，很恶心 https://blog.csdn.net/fuxuemingzhu/article/details/82389223
791. Custom Sort String Medium 统计次数，拼接成字符串 https://blog.csdn.net/fuxuemingzhu/article/details/79378688
442. Find All Duplicates in an Array Medium 原地变成负数，如果已经是负数，那么说明出现了两次。 https://blog.csdn.net/fuxuemingzhu/article/details/79275549
355. Design Twitter Medium 使用优先级队列弹出最新的内容 https://blog.csdn.net/fuxuemingzhu/article/details/82155420
841. Keys and Rooms Medium 可以使用DFS和BFS解决 https://blog.csdn.net/fuxuemingzhu/article/details/80476862
406. Queue Reconstruction by Height Medium 先插入长得高的他们不会影响别人，然后在对应位置插入次高的 https://blog.csdn.net/fuxuemingzhu/article/details/68486884
513. Find Bottom Left Tree Value Medium 层次遍历，找出最后一层的第一个节点即可 https://blog.csdn.net/fuxuemingzhu/article/details/70161829
739. Daily Temperatures Medium 使用一个栈，保存每个元素，如果后面的元素比较大，那么就已知出栈操作 https://blog.csdn.net/fuxuemingzhu/art

继续阅读与本文标签相同的文章

无标签
最新文章 最热文章
收藏 打印

特别推荐 2026年05月18日 星期一

精彩发现

热门标签

阻止表单提交 窗口 关闭浏览器 清除 CDATA css文件 光标位置 坐标 javascrpt !important 超链接 数字

相关文章

热门标签
1阻止表单提交 1篇
2窗口 1篇
3关闭浏览器 1篇
4清除 1篇
5CDATA 1篇
6css文件 1篇
7光标位置 1篇
8坐标 1篇
9javascrpt 1篇
10!important 1篇
11超链接 2篇
12数字 1篇
13Enter 1篇
14自定义 1篇
15pdf 1篇
16嵌套 1篇
17Flexbox 1篇
18包含 1篇
19href 1篇
20自动填充 1篇
21html敏捷包 1篇
22enctype 1篇
23水平垂直居中 1篇
24百分比 1篇
25placeholder 1篇
26相同高度 2篇
27并排div 2篇
28样式 2篇
29innerHTML 1篇
30pdf文件 1篇
31html文件 1篇
32选择框 1篇
33屏幕可见区 1篇
34DOM元素 2篇
35按钮 2篇
36手机 1篇
您的足迹：