# python-algorithm

**Repository Path**: mark2root/python-algorithm

## Basic Information

- **Project Name**: python-algorithm
- **Description**: 老宋秋招刷题日记， 语言使用python 与 c++ 
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2021-12-10
- **Last Updated**: 2021-12-10

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

## Introduction

本仓库是我在准备 2020 届秋招时所刷过的题，刷题对于找工作的重要性不言而喻， 如果你现在还没有开始，我的建议是从明天开始，一天5道。 如果你按照我的这个仓库的目录进行刷题，刷个两三遍，对于每道题都能很快的产生思路， 那么毕业找工作的时候，BAT 面试时候的手撸算法这关，你是完全没有问题的。 

该仓库大概包含 300+ 道编程题， 是由我个人筛选的， 基本所有的知识点都有涉及到，目前仓库还在更新中，预计12月底完成。

- docs： 该文件夹下包含了诸多数据结构基础知识，如果对哪一方面不熟悉可以参考一下

[TOC]



## 1. 链表

### 1. 剑指 offer

| [offer 6: 从头到尾打印链表](https://www.nowcoder.com/practice/d0267f7f55b3412ba93bd35cfa8e8035?tpId=13&tqId=11156&tPage=1&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking) | [offer 18 :删除链表中重复的节点](<https://www.nowcoder.com/practice/fc533c45b73a41b0b44ccba763f866ef?tpId=13&tqId=11209&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking>) | [offer 22: 链表中的倒数第 k 个节点](<https://www.nowcoder.com/practice/529d3ae5a407492994ad2a246518148a?tpId=13&tqId=11167&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [offer 23: 链表中环的入口节点](<https://www.nowcoder.com/practice/253d2c59ec3e4bc68da16833f79a38e4?tpId=13&tqId=11208&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking>) | [offer 25: 反转链表](<https://www.nowcoder.com/practice/75e878df47f24fdc9dc3e400ec6058ca?tpId=13&tqId=11168&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking>) | [offer 25: 合并两个排序的链表](<https://www.nowcoder.com/practice/d8b6b4358f774294a89de2a6ac4d9337?tpId=13&tqId=11169&tPage=1&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) |
| [offer 35: 复杂链表的复制](<https://www.nowcoder.com/practice/f836b2c43afc4b35ad6adc41ec941dba?tpId=13&tqId=11178&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [offer 52: 两个链表的第一个公共节点](<https://www.nowcoder.com/practice/6ab1d9a29e88450685099d45c9e31e46?tpId=13&tqId=11189&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) |                                                              |

### 2. Leetcode Easy

| [leetcode 206: 反转链表](<https://leetcode-cn.com/problems/reverse-linked-list/>) | [leetcode 160: 链表相交](<https://leetcode-cn.com/problems/intersection-of-two-linked-lists/>) | [leetcode 21: 排序链表的合并](<https://leetcode-cn.com/problems/merge-two-sorted-lists/>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [leetcode 234: 回文链表](<https://leetcode-cn.com/problems/palindrome-linked-list/>) | [leetcode 237: 删除链表中的节点](<https://leetcode-cn.com/problems/delete-node-in-a-linked-list/>) | [leetcode 83: 删除排序链表中重复的节点](<https://leetcode-cn.com/problems/remove-duplicates-from-sorted-list/>) |
| [leetcode 203: 移除链表元素](<https://leetcode-cn.com/problems/remove-linked-list-elements/submissions/>) |                                                              |                                                              |

### 3. Leetcode Medium

| [leetcode 92:反转链表](<https://leetcode-cn.com/problems/reverse-linked-list-ii/>) | [leetcode 141: 环形链表](<https://leetcode-cn.com/problems/linked-list-cycle/>) | [leetcode 142: 环形链表2](<https://leetcode-cn.com/problems/linked-list-cycle-ii/>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [leetcode 86: 链表划分](<https://leetcode-cn.com/problems/partition-list/>) | [leetcode 138: 复制带随机指针的链表](<https://leetcode-cn.com/problems/copy-list-with-random-pointer/>) | [leetcode 2: 两数相加](<https://leetcode-cn.com/problems/add-two-numbers/>) |
| [leetcode 148:排序链表](<https://leetcode-cn.com/problems/sort-list/>) | [leetcode 328: 奇偶链表](<https://leetcode-cn.com/problems/odd-even-linked-list/submissions/>) | [leetcode 445: 两数相加2](<https://leetcode-cn.com/problems/add-two-numbers-ii/>) |
| [leetcode 82: 删除排序链表中的重复元素2](<https://leetcode-cn.com/problems/remove-duplicates-from-sorted-list-ii/submissions/>) | [leetcode 24: 两两交换链表中的节点](<https://leetcode-cn.com/problems/swap-nodes-in-pairs/submissions/>) | [leetcode 147: 对链表进行插入排序](<https://leetcode-cn.com/problems/insertion-sort-list/>) |
| [leetcode 148: 排序链表](<https://leetcode-cn.com/problems/sort-list/>) | [leetcode 19: 删除链表的倒数第 N 个节点](<https://leetcode-cn.com/problems/remove-nth-node-from-end-of-list/>) | [leetcode 61: 旋转链表](<https://leetcode-cn.com/problems/rotate-list/>) |
| [leetcode 143: 重排链表](<https://leetcode-cn.com/problems/reorder-list/>) |                                                              |                                                              |

### 4. Leetcode Hard

| [leetcode 23: 合并 k 个有序链表](<https://leetcode-cn.com/problems/merge-k-sorted-lists/>) | [leetcode 25: k 个一组翻转链表](<https://leetcode-cn.com/problems/reverse-nodes-in-k-group/>) |      |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ---- |
|                                                              |                                                              |      |

## 2. 数组

### 1. 剑指 offer

| [offer 3：数组中重复的数字](https://www.nowcoder.com/practice/623a5ac0ea5b4e5f95552655361ae0a8?tpId=13&tqId=11203&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking) | [offer 4：二维数组的查找](https://www.nowcoder.com/practice/abc3fe2ce8e146608e868a70efebf62e?tpId=13&tqId=11154&tPage=1&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking) | [offer 11: 旋转数组中的最小数字](<https://www.nowcoder.com/practice/9f3231a991af4f55b95579b44b7a01ba?tpId=13&tqId=11159&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [offer 21: 调整数组的顺序](<https://www.nowcoder.com/practice/beb5aa231adc45b2a5dcc5b62c93f593?tpId=13&tqId=11166&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking>) | [offer 39: 数组中出现次数超过一半的数字](<https://www.nowcoder.com/practice/e8a1b01a2df14cb2b228b30ee6a92163?tpId=13&tqId=11181&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [offer 40: 最小 k 个数](<https://www.nowcoder.com/practice/6a296eb82cf844ca8539b57c23e6e9bf?tpId=13&tqId=11182&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) |
| [offer 41: 数据流中的中位数](<https://www.nowcoder.com/practice/9be0172896bd43948f8a32fb954e1be1?tpId=13&tqId=11216&tPage=4&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [offer 42: 连续子数组的最大和](<https://www.nowcoder.com/practice/459bd355da1549fa8a49e350bf3df484?tpId=13&tqId=11183&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [offer 43: 1出现的次数](<https://leetcode-cn.com/problems/number-of-digit-one/>) |
| [offer 44: 数字序列中的某一位数字](<https://leetcode-cn.com/problems/nth-digit/>) | [offer 45: 把数组排成最小的数](<https://www.nowcoder.com/practice/8fecd3f8ba334add803bf2a06af1b993?tpId=13&tqId=11185&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [offer 46: 把数字翻译成字符串](<https://leetcode-cn.com/problems/decode-ways/>) |
| [offer 51: 数组中的逆序对](<https://www.nowcoder.com/practice/96bd6684e04a44eb80e6a68efc0ec6c5?tpId=13&tqId=11188&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [offer 53: 排序数组中查找数字](<https://www.nowcoder.com/practice/70610bf967994b22bb1c26f9ae901fa2?tpId=13&tqId=11190&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [offer 56：数组中只出现一次的两个数字](<https://leetcode-cn.com/problems/single-number/>) |
| [offer 57：和为 s 的两个数字](<https://www.nowcoder.com/practice/390da4f7a00f44bea7c2f3d19491311b?tpId=13&tqId=11195&tPage=3&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [offer 61：扑克牌的顺子](<https://www.nowcoder.com/practice/762836f4d43d43ca9deb273b3de8e1f4?tpId=13&tqId=11198&tPage=3&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [offer 63: 股票的最大利润](<https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock/>) |
| [offer 66: 构建乘积数组](<https://leetcode-cn.com/problems/product-of-array-except-self/>) | [offer 59：滑动窗口最大值](<https://www.nowcoder.com/practice/1624bc35a45c42c0bc17d17fa0cba788?tpId=13&tqId=11217&tPage=4&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) |                                                              |

### 2. Leetcode Easy

| [leetcode 283: 移动零](<https://leetcode-cn.com/problems/move-zeroes/>) | [leetcode 27: 移除元素](<https://leetcode-cn.com/problems/remove-element/>) | [leetcode 26:删除排序数组中的重复项](<https://leetcode-cn.com/problems/remove-duplicates-from-sorted-array/>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [leetcode 88: 合并两个有序数组](<https://leetcode-cn.com/problems/merge-sorted-array/>) | [leetcode 167: 两数之和 2](<https://leetcode-cn.com/problems/two-sum-ii-input-array-is-sorted/>) | [leetcode 400: 第 N 个数](<https://leetcode-cn.com/problems/nth-digit/>) |
| [leetcode 1: 两数之和](<https://leetcode-cn.com/problems/two-sum/>) | [leetcode 121: 买卖股票的最佳时机](<https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock/>) | [leetcode 136: 只出现一次的数字](<https://leetcode-cn.com/problems/single-number/>) |
| [leetcode 169: 求众数](<https://leetcode-cn.com/problems/majority-element/>) | [leetcode 448: 找到所有数组中消失的数字](<https://leetcode-cn.com/problems/find-all-numbers-disappeared-in-an-array/>) | [leetcode 581: 最短无序连续子数组](<https://leetcode-cn.com/problems/shortest-unsorted-continuous-subarray/>) |
|                                                              |                                                              |                                                              |

### 3. Leetcode Medium

| [leetcode 80: 删除排序数组中的重复项2](<https://leetcode-cn.com/problems/remove-duplicates-from-sorted-array-ii/>) | [leetcode 75: 颜色分类](<https://leetcode-cn.com/problems/sort-colors/>) | [leetcode 215: 数组中的第 k 个最大元素](<https://leetcode-cn.com/problems/kth-largest-element-in-an-array/>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [leetcode 11: 盛最多水的容器](<https://leetcode-cn.com/problems/container-with-most-water/>) | [leetcode 209: 长度最小的子数组](<https://leetcode-cn.com/problems/minimum-size-subarray-sum/>) | [leetcode 238: 除自身之外的乘积](<https://leetcode-cn.com/problems/product-of-array-except-self/>) |
| [leetcode 91: 解码方法](<https://leetcode-cn.com/problems/decode-ways/>) | [leetcode 15: 三数之和](<https://leetcode-cn.com/problems/3sum/>) | [leetcode 287: 寻找重复数](<https://leetcode-cn.com/problems/find-the-duplicate-number/>) |
| [leetcode 338: 比特位计数](<https://leetcode-cn.com/problems/counting-bits/>) | [leetcode 347: 前 k 个高频元素](<https://leetcode-cn.com/problems/top-k-frequent-elements/>) | [leetcode 406: 根据身高重建队列](<https://leetcode-cn.com/problems/queue-reconstruction-by-height/>) |
| [leetcode 523: 连续的子数组和](<https://leetcode-cn.com/problems/continuous-subarray-sum/>) | [leetcode 739: 每日温度](<https://leetcode-cn.com/problems/daily-temperatures/>) | [leetcode 795: 区间子数组个数](<https://leetcode-cn.com/problems/number-of-subarrays-with-bounded-maximum/>) |

### 4. Leetcode Hard

| [leetcode 128: 最长连续序列](<https://leetcode-cn.com/problems/longest-consecutive-sequence/>) |      |      |
| ------------------------------------------------------------ | ---- | ---- |
|                                                              |      |      |



## 3. 字符串



### 1.  剑指 offer



### 2. Leetcode Easy

| [leetcode 344: 反转字符串](<https://leetcode-cn.com/problems/reverse-string/>) | [leetcode 345: 反转字符串中的元音字母](<https://leetcode-cn.com/problems/reverse-vowels-of-a-string/>) | [leetcode 438: 找到字符串中的所有字母异位词](<https://leetcode-cn.com/problems/find-all-anagrams-in-a-string/>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
|                                                              |                                                              |                                                              |
|                                                              |                                                              |                                                              |

### 3. Leetcode Medium

| [leetcode 3: 无重复字符的最长子串](<https://leetcode-cn.com/problems/longest-substring-without-repeating-characters/>) |      |      |
| ------------------------------------------------------------ | ---- | ---- |
|                                                              |      |      |

### 4. Leetcode Hard

| [leetcode 76: 最小覆盖子串](<https://leetcode-cn.com/problems/minimum-window-substring/>) |      |      |
| ------------------------------------------------------------ | ---- | ---- |
|                                                              |      |      |



## 4. 回文串

### 1. Leetcode Easy

| [leetcode 125: 验证回文串](<https://leetcode-cn.com/problems/valid-palindrome/>) |      |      |
| ------------------------------------------------------------ | ---- | ---- |
|                                                              |      |      |



## 5. 栈-队列-堆

### 1. 剑指 offer

| [offer 9: 两个栈实现队列](<https://www.nowcoder.com/practice/54275ddae22f475981afa2244dd448c6?tpId=13&tqId=11158&tPage=1&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [offer 9： 两个队列实现一个栈](<https://leetcode-cn.com/problems/implement-stack-using-queues/>) | [offer 30：包含 min 函数的栈](<https://www.nowcoder.com/practice/4c776177d2c04c2494f2555c9fcc1e49?tpId=13&tqId=11173&tPage=1&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [offer 31：栈的压入，弹出序列](<https://www.nowcoder.com/practice/d77d11405cc7470d82554cb392585106?tpId=13&tqId=11174&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) |                                                              |                                                              |

### 2. Leetcode Easy

| [leetcode 225: 用队列实现栈](<https://leetcode-cn.com/problems/implement-stack-using-queues/>) | [leetcode 232: 用栈实现队列](<https://leetcode-cn.com/problems/implement-queue-using-stacks/>) | [leetcode 155: 最小栈](<https://leetcode-cn.com/problems/min-stack/>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [leetcode 20: 有效的括号](<https://leetcode-cn.com/problems/valid-parentheses/>) |                                                              |                                                              |

### 3. Leetcode Medium

| [leetcode 215: 数组中的第 k 个最大元素](<https://leetcode-cn.com/problems/kth-largest-element-in-an-array/>) | [leetcode 946: 验证栈序列](<https://leetcode-cn.com/problems/validate-stack-sequences/>) |      |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ---- |
|                                                              |                                                              |      |

### 4. Leetcode Hard

| [leetcode 224: 基本计算器](<https://leetcode-cn.com/problems/basic-calculator/>) | [leetcode 295: 数据流的中位数](<https://leetcode-cn.com/problems/find-median-from-data-stream/>) |      |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ---- |
|                                                              |                                                              |      |

## 6. 二叉树

### 1. 剑指offer

| [重建二叉树](https://www.nowcoder.com/practice/8a19cbe657394eeaac2f6ea9b0f6fcf6?tpId=13&tqId=11157&tPage=1&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking) | [二叉树的下一个节点](https://www.nowcoder.com/practice/9023a0c988684a53960365b889ceaf5e?tpId=13&tqId=11210&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking) | [树的子结构](<https://www.nowcoder.com/practice/6e196c44c7004d15b1610b9afca8bd88?tpId=13&tqId=11170&tPage=1&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [二叉树的镜像](<https://www.nowcoder.com/practice/564f4c26aa584921bc75623e48ca3011?tpId=13&tqId=11171&tPage=1&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [对称的二叉树](<https://www.nowcoder.com/practice/ff05d44dfdb04e1d83bdbdab320efbcb?tpId=13&tqId=11211&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking>) | [不分行从上到下打印二叉树](<https://www.nowcoder.com/practice/7fe2212963db4790b57431d9ed259701?tpId=13&tqId=11175&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) |
| [分行从上到下打印二叉树](<https://www.nowcoder.com/practice/445c44d982d04483b04a54f298796288?tpId=13&tqId=11213&tPage=3&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [之字形打印二叉树](<https://www.nowcoder.com/practice/91b69814117f4e8097390d107d2efbe0?tpId=13&tqId=11212&tPage=3&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [二叉树的后序遍历序列](<https://www.nowcoder.com/practice/a861533d45854474ac791d90e447bafd?tpId=13&tqId=11176&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) |
| [二叉树中和为某一值的路径](<https://www.nowcoder.com/practice/b736e784e3e34731af99065031301bca?tpId=13&tqId=11177&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [二叉搜索树转化为双向链表](<https://www.nowcoder.com/practice/947f6eb80d944a84850b0538bf0ec3a5?tpId=13&tqId=11179&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [序列化二叉树](<https://www.nowcoder.com/practice/cf7e25aa97c04cc1a68c8f040e71fb84?tpId=13&tqId=11214&tPage=4&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) |
| [二叉搜索树的第 k 大节点](<https://www.nowcoder.com/practice/ef068f602dde4d28aab2b210e859150a?tpId=13&tqId=11215&tPage=4&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [二叉树的深度](<https://www.nowcoder.com/practice/435fb86331474282a3499955f0a41e8b?tpId=13&tqId=11191&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking>) | [平衡二叉树](<https://www.nowcoder.com/practice/8b3b95850edb4115918ecebdf1b4d222?tpId=13&tqId=11192&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) |

### 2. Leetcode Easy

| [leetcode 104: 二叉树最大深度](<https://leetcode-cn.com/problems/maximum-depth-of-binary-tree/>) | [leetcode 111：二叉树的最小深度](<https://leetcode-cn.com/problems/minimum-depth-of-binary-tree/>) | [leetcode 226 :翻转二叉树](<https://leetcode-cn.com/problems/invert-binary-tree/>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [leetcode 100: 相同的树](<https://leetcode-cn.com/problems/same-tree/>) | [leetcode 112: 路径总和](<https://leetcode-cn.com/problems/path-sum/submissions/>) | [leetcode 404: 左叶子之和](<https://leetcode-cn.com/problemset/all/?search=404>) |
| [leetcode 257: 二叉树所有路径](<https://leetcode-cn.com/problems/binary-tree-paths/>) | [leetcode 437: 路径总和3](<https://leetcode-cn.com/problems/path-sum-iii/>) | [leetcode 235: 二叉搜索树的最近公共祖先](<https://leetcode-cn.com/problems/lowest-common-ancestor-of-a-binary-search-tree/>) |
| [leetcode 108: 将有序数组转化为二叉搜索树](<https://leetcode-cn.com/problems/convert-sorted-array-to-binary-search-tree/>) |                                                              |                                                              |

### 3. Leetcode Medium

| [leetcode 144: 二叉树前序遍历](<https://leetcode-cn.com/problems/binary-tree-preorder-traversal/>) | [leetcode 94: 二叉树的中序遍历](<https://leetcode-cn.com/problems/binary-tree-inorder-traversal/>) | [leetcode 102: 二叉树的层序遍历](<https://leetcode-cn.com/problems/binary-tree-level-order-traversal/>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [leetcode 96: 不同的二叉搜索树](<https://leetcode-cn.com/problems/unique-binary-search-trees/>) | [leetcode 105: 从前序和中序遍历构造二叉树](<https://leetcode-cn.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/>) | [leetcode 98: 二叉搜索树](<https://leetcode-cn.com/problems/validate-binary-search-tree/>) |
| [leetcode 333: 最大BST子树](<https://leetcode-cn.com/problems/largest-bst-subtree/>) | [leetcode 958:完全二叉树](<https://leetcode-cn.com/problems/check-completeness-of-a-binary-tree/>) | [leetcode 110: 平衡二叉树](<https://leetcode-cn.com/problems/balanced-binary-tree/>) |
| [leetcode 543: 二叉树的直径](<https://leetcode-cn.com/problems/diameter-of-binary-tree/>) | [leetcode 222: 完全二叉树节点个数](<https://leetcode-cn.com/problems/count-complete-tree-nodes/>) | [leetcode 1038: 从二叉搜索树到更大和树](<https://leetcode-cn.com/problems/binary-search-tree-to-greater-sum-tree/>) |
| [leetcode 662: 二叉树最大宽度](<https://leetcode-cn.com/problems/maximum-width-of-binary-tree/>) | [leetcode 101: 对称二叉树](<https://leetcode-cn.com/problems/symmetric-tree/>) | [leetcode 199:二叉树的右视图](<https://leetcode-cn.com/problems/binary-tree-right-side-view/>) |
| [leetcode 113: 路径总和 2](<https://leetcode-cn.com/problems/path-sum-ii/>) | [leetcode 129: 求根到叶子节点数字之和](<https://leetcode-cn.com/problems/sum-root-to-leaf-numbers/>) | [leetcode 450: 删除二叉搜索树中的节点]()                     |
| [leetcode 230: 二叉搜索树中的第 k 小的元素](<https://leetcode-cn.com/problems/kth-smallest-element-in-a-bst/>) | [leetcode 236: 二叉树的最近公共祖先](<https://leetcode-cn.com/problems/lowest-common-ancestor-of-a-binary-tree/>) |                                                              |
|                                                              |                                                              |                                                              |

### 4.  Leetcode Hard

| [leetcode 145: 二叉树的后序遍历](<https://leetcode-cn.com/problems/binary-tree-postorder-traversal/>) |      |      |
| ------------------------------------------------------------ | ---- | ---- |
|                                                              |      |      |





## 查找问题

这里指的查找问题主要包括以下两类：

- 查找元素 `a` 是否存在？ 一般采用集合 Set 来做。
- 查找元素 `a` 出现了几次？ 一般采用字典 Dict 来做。

### 1. 剑指offer



### 2. Leetcode Easy

| [leetcode 349: 两个数组的交集](<https://leetcode-cn.com/problems/intersection-of-two-arrays/>) | [leetcode 350: 两个数组的交集 2](<https://leetcode-cn.com/problems/intersection-of-two-arrays-ii/>) | [leetcode 242: 有效的字母异位词](<https://leetcode-cn.com/problems/valid-anagram/>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [leetcode 202: 快乐数](<https://leetcode-cn.com/problems/happy-number/>) | [leetcode 290: 单词规律](<https://leetcode-cn.com/problems/word-pattern/>) | [leetcode 205: 同构字符串](<https://leetcode-cn.com/problems/isomorphic-strings/>) |
| [leetcode 1: 两数之和](<https://leetcode-cn.com/problems/two-sum/>) | [leetcode 447: 回旋镖的数量](<https://leetcode-cn.com/problems/number-of-boomerangs/>) | [leetcode 219: 存在重复元素2](<https://leetcode-cn.com/problems/contains-duplicate-ii/>) |
| [leetcode 217:存在重复元素](<https://leetcode-cn.com/problems/contains-duplicate/>) |                                                              |                                                              |

### 3. Leetcode Medium

| [leetcode 451: 根据字符出现频率排序](<https://leetcode-cn.com/problems/sort-characters-by-frequency/>) | [leetcode 15: 三数之和](<https://leetcode-cn.com/problems/3sum/>) | [leetcode 16: 最接近的三数之和](<https://leetcode-cn.com/problems/3sum-closest/>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [leetcode 454: 四数相加2](<https://leetcode-cn.com/problems/4sum-ii/>) | [leetcode 49: 字母异位词分组](<https://leetcode-cn.com/problems/group-anagrams/>) | [leetcode 220:存在重复元素3](<https://leetcode-cn.com/problems/contains-duplicate-iii/>) |
|                                                              |                                                              |                                                              |
|                                                              |                                                              |                                                              |

### 4. Leetcode Hard

| [leetcode 149: 直线上最多的点数](<https://leetcode-cn.com/problems/max-points-on-a-line/>) |      |      |
| ------------------------------------------------------------ | ---- | ---- |
|                                                              |      |      |

## 二分查找

### 1. 剑指offer



### 2. Leetcode Easy

| [leetcode 704: 二分查找](<https://leetcode-cn.com/problems/binary-search/>) |      |      |
| ------------------------------------------------------------ | ---- | ---- |
|                                                              |      |      |







## 回溯法

### 1. 剑指offer

| [offer 12: 矩阵中的路径](<https://www.nowcoder.com/practice/c61c6999eecb4b8f88a98f66b273a3cc?tpId=13&tqId=11218&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking>) | [offer  13: 机器人的运动范围](<https://www.nowcoder.com/practice/6e5207314b5241fb83f2329e89fdecc8?tpId=13&tqId=11219&tPage=4&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [offer 64: 求1+...+n](<https://www.nowcoder.com/practice/7a0da8fc483247ff8800059e12d7caf1?tpId=13&tqId=11200&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
|                                                              |                                                              |                                                              |

### 2. Leetcode Easy

| [leetcode 401: 二进制手表](<https://leetcode-cn.com/problems/binary-watch/>) | [leetcode 784: 字母大小写全排列](<https://leetcode-cn.com/problems/letter-case-permutation/>) |      |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ---- |
|                                                              |                                                              |      |

### 3. Leetcode Medium

| [Leetcode 17: 电话号码的字母组合](<https://leetcode-cn.com/problems/letter-combinations-of-a-phone-number/>) | [leetcode 131: 分割回文串](<https://leetcode-cn.com/problems/palindrome-partitioning/>) | [leetcode 45: 全排列](<https://leetcode-cn.com/problems/permutations/>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [leetcode 47： 全排列2](<https://leetcode-cn.com/problems/permutations-ii/>) | [leetcode 77: 组合](<https://leetcode-cn.com/problems/combinations/>) | [leetcode 39: 组合总和](<https://leetcode-cn.com/problems/combination-sum/>) |
| [leetcode 40: 组合总和2](<https://leetcode-cn.com/problems/combination-sum-ii/>) | [leetcode 216:组合总和3](<https://leetcode-cn.com/problems/combination-sum-iii/>) | [leetcode 78:子集](<https://leetcode-cn.com/problems/subsets/>) |
| [leetcode 90: 子集2](<https://leetcode-cn.com/problems/subsets-ii/>) | [leetcode 79: 单词搜索](<https://leetcode-cn.com/problems/word-search/>) | [leetcode 200: 岛屿数量](<https://leetcode-cn.com/problems/number-of-islands/>) |
| [leetcode 130: 被围绕的区域](<https://leetcode-cn.com/problems/surrounded-regions/>) | [leetcode 417: 太平洋大西洋水流问题](<https://leetcode-cn.com/problems/pacific-atlantic-water-flow/>) | [leetcode 207: 课程表](<https://leetcode-cn.com/problems/course-schedule/>) |
|                                                              |                                                              |                                                              |

### 4. Leetcode Hard

| [leetcode 51: N皇后问题](<https://leetcode-cn.com/problems/n-queens/>) | [leetcode 52: N皇后问题2](<https://leetcode-cn.com/problems/n-queens-ii/>) | [leetcode 37: 解数独](<https://leetcode-cn.com/problems/sudoku-solver/>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
|                                                              |                                                              |                                                              |



## 贪心算法

### 1. Leetcode Easy

| [leetcode 944: 删列造序](<https://leetcode-cn.com/problems/delete-columns-to-make-sorted/>) | [leetcode 1046: 最后一块石头的重量](<https://leetcode-cn.com/problems/last-stone-weight/>) | [leetcode 122: 买卖股票的最佳时机2]() |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------- |
|                                                              |                                                              |                                       |
|                                                              |                                                              |                                       |
|                                                              |                                                              |                                       |







## 动态规划

### 1. 剑指 offer

| [斐波那契数列](<https://www.nowcoder.com/practice/c6c7742f5ba7442aada113136ddea0c3?tpId=13&tqId=11160&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking>) | [青蛙跳台阶问题](<https://www.nowcoder.com/practice/8c82a5b80378478f9484d87d1c5f12a4?tpId=13&tqId=11161&tPage=1&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [变态跳台阶](<https://www.nowcoder.com/practice/22243d016f6b47f2a6928b4313c85387?tpId=13&tqId=11162&tPage=1&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [矩形覆盖](<https://www.nowcoder.com/practice/72a5a919508a4251859fb2cfb987a0e6?tpId=13&tqId=11163&tPage=1&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) | [剪绳子](<https://leetcode-cn.com/problems/integer-break/>)  | [offer 49: 丑数](<https://www.nowcoder.com/practice/6aa9e04fc3794f68acf8778237ba065b?tpId=13&tqId=11186&tPage=2&rp=1&ru=%2Fta%2Fcoding-interviews&qru=%2Fta%2Fcoding-interviews%2Fquestion-ranking>) |
|                                                              |                                                              |                                                              |
|                                                              |                                                              |                                                              |

### 2. Leetcode Easy

| [leetcode 1025:除数博弈](<https://leetcode-cn.com/problems/divisor-game/>) | [leetcode 70: 爬楼梯](<https://leetcode-cn.com/problems/climbing-stairs/>) | [leetcode 198:打家劫舍](<https://leetcode-cn.com/problems/house-robber/>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [leetcode 53](<https://leetcode-cn.com/problems/maximum-subarray/>) |                                                              |                                                              |
|                                                              |                                                              |                                                              |

### 3. Leetcode Medium

| [leetcode 322: 零钱兑换](<https://leetcode-cn.com/problems/coin-change/>) | [leetcode 120: 三角形最小路径和](<https://leetcode-cn.com/problems/triangle/>) | [leetcode 300: 最长上升子序列](<https://leetcode-cn.com/problems/longest-increasing-subsequence/>) |
| ------------------------------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
| [leetcode 64: 最小路径和](<https://leetcode-cn.com/problems/minimum-path-sum/>) |                                                              |                                                              |
|                                                              |                                                              |                                                              |

### 4. Hard

| [leetcode 174: 地下城游戏](<https://leetcode-cn.com/problems/dungeon-game/>) |      |      |
| :----------------------------------------------------------- | ---- | ---- |
|                                                              |      |      |