算法题刷题笔记

深藏阁楼爱情的钟 2024-03-27 11:33 59阅读 0赞

## 在线题库 ##

> **[牛客华为机试题库【题号 HJ开头】（重点看）][HJ]**  
> **[牛客在线编程算法篇【题号NC开头】][NC]**  
> **[剑指offer【题号 JZ开头】][offer_ JZ]**  
> **[力扣][Link 1]**  
> 重点刷牛客网华为机试题库，时间充裕可以辅助刷力扣和剑指offer

--------------------

## 专题总结 ##

**[Java 语言学正则表达式][Java]**  
**[Java 进制转换算法][Java 1]**  
**[Java 数学常用方法][Java 2]**  
[Java 业务原子级常用方法][Java 3]

**[Java 字符常用方法][Java 4]**

**[Java8 Stream 流常用方法][Java8 Stream]**

**[Java 字符串，数组，集合之间相互转换][Java 5]**  
**[Java 数组，List，Map排序][Java _List_Map]**  
**[Java 数组常用方法][Java 6]**

**[递归算法专题][Link 2]**  
**[位运算专题][Link 3]**  
**[二叉树二叉堆专题][Link 4]**

[算法优化 遍历不回头的场景][Link 5]  
[数组指针遍历 学习总结][Link 6]  
**[数组双指针遍历场景][Link 7]**

[DFS & BFS 学习总结][DFS _ BFS]  
[DFS 学习笔记][DFS]

### 字符串操作 ###

**\[简单\] [HJ2 计算某字符出现次数][HJ2]**  
 **\[简单\]  [HJ10.字符个数统计][HJ10.]**  
 **\[简单\] \*[HJ23.删除字符串中出现次数最少的字符][HJ23.]**  
 **\[入门\] [HJ9 提取不重复的整数][HJ9]**  
**\[真题\] [字符串加密][Link 8]**

**\[简单\] [HJ11 数字颠倒][HJ11]**  
 **\[简单\] [HJ12 字符串反转][HJ12]**  
 **\[简单\] [HJ13 句子逆序][HJ13]**  
**\[真题\] [按单词下标区间翻转文章内容][Link 9]**

\[简单\] [HJ1 字符串最后一个单词的长度][HJ1]  
 \[入门\] [HJ46 截取字符串][HJ46]  
\[真题\] [字符串分割][Link 10]  
 \[简单\] [HJ4 字符串分隔][HJ4]  
\[真题\] [求字符串中所有整数的最小和][Link 11]

**\[中等\]  [HJ17.坐标移动][HJ17.]**  
[【算法题】键键盘的输出][Link 12]  
[【算法题】考勤信息][Link 13]  
 **\[中等\]  [HJ20.密码验证合格程序][HJ20.]**  
 \[中等\]  [NC100 字符串转换成整数][NC100]

#### 子串&子序列 ####

\[简单\] [leetcode392 判断字符串 s 是否为 t 的子序列][leetcode392 _ s _ t] s = “abc”, t = “ahbgdc” → true  
\[真题\] [ 连续字母长度][Link 14]  
\[真题\] [非严格递增连续数字序列][Link 15]

\[中等\]  [HJ65 查找两个字符串a,b中的最长公共子串][HJ65 _a_b]  
 \[中等\]  [NC149字符串匹配KMP算法][NC149_KMP] **需要理解**

\[中等\]  [NC17.最长回文子串][NC17.]  
 \[较难\]  [NC28.最小覆盖子串][NC28.]

> 混淆名词区分  
> 严格递增子序列：1 2 3  
> 非严格递增子序列：1 2 2 3  
> 连续递增子序列： 1 3 5 7 9 → 1 3 5 7  
> 数字连续递增子序列：1 2 3 4 5 2 3 → 1 2 3 4 5  
> 递增子序列：1 3 6 2 7 → 1 3 6 7

\[简单\] \*[leetcode674. 无序整数数组，最长连续递增序列][leetcode674.] \[1,3,5,4,7\]→\[1,3,5\]  
无序整数数组，最长连续严格递增序列的长度（leetcode 674） \[1,3,5,4,7\]→\[1,3,5\]→3  
 \[中等\] [leetcode128 无序整数数组，最长数字连续递增序列的长度][leetcode128] \[100,4,200,1,3,2\]→\[1, 2, 3, 4\]→4  
 \[中等\]  [leetcode1839 所有元音按顺序排布的最长子字符串][leetcode1839]

\[中等\] [leetcode491 无序整数数组，找出所有 非严格递增 子序列][leetcode491 _ _] \[4,6,7,7\]→\[\[4,6\],\[4,6,7\],\[4,6,7,7\],\[4,7\],\[4,7,7\],\[6,7\],\[6,7,7\],\[7,7\]\] （严格递增仅>和>=的区别）\[4,6,7,7\]→\[\[4,6\],\[4,6,7\],\[4,7\],\[6,7\]\]  
 \[中等\] [leetcode300 无序整数数组，找出严格递增最长子序列的长度][leetcode300] \[10,9,2,5,3,7,101,18\]→\[2,3,7,101\]→4（非严格递增仅>和>=的区别）

### 数组 ###

\[真题\] [乱序整数序列两数之和绝对值最小][Link 16]  
\[真题\] [整数对最小和][Link 17]  
\[真题\] [检查是否存在满足条件的数字组合][Link 18]  
 \[中等\] [ HJ41.称砝码][HJ41.]

\[真题\] [数组拼接][Link 19]

### 查找排序 ###

\[较难?\]  [HJ3.明明的随机数][HJ3.]  
 \[入门\]  [HJ101.输入整型数组和排序标识][HJ101.]  
 \[较难?\] \*[HJ68.成绩排序][HJ68.]  
 \[入门\] [HJ58 输入n个整数，输出其中最小的k个][HJ58 _n_k]

\[简单\]  [HJ8.合并表记录][HJ8.]  
 \[简单\]  \*[HJ14.字符串排序][HJ14.]  
\[真题\] [统计射击比赛成绩][Link 20]

\[中等\]  [HJ27.查找兄弟单词][HJ27.]  
 \[中等\] \*[NC37.合并区间][NC37.]

\[中等\]  [JZ4 二维数组中的查找][JZ4]

### 栈 ###

\[简单\]  \*[leetcode 1614.括号的最大嵌套深度][leetcode 1614.]  
 \[简单\]  [NC52.括号序列][NC52.]  
 \[中等\]  [NC175合法的括号字符串][NC175]  
 \[中等\]  [HJ70 矩阵乘法计算量估算][HJ70]  
[【算法题】仿LISP运算][LISP]

### 队列 ###

[【算法题】贪吃蛇][Link 21]

### TopK问题 ###

\[困难\] [239. 滑动窗口最大值][239.]

### DFS ###

#### 排列组合 ####

\[中等\]  [leetcode 面试题 08.07. 无重复字符串的排列组合][leetcode _ 08.07.]  
 \[中等\]  \* [leetcode 面试题08.08.有重复字符串的排列组合][leetcode _08.08.]  
 \[中等\]  [leetcode 77.组合][leetcode 77.]  
 \[中等\] [leetcode491 整数数组，找不同的递增子序列][leetcode491 _ _]  
 \[中等\] 整数数组，找不同的严格递增子序列 （leetcode491一样实现仅>和>=的区别）

##### (9) 岛屿问题（技术面试高频考点） #####

\[中等\]  [leetcode200. 岛屿数量][leetcode200.]  
 \[简单\]  [leetcode463. 岛屿的周长][leetcode463.]  
 \[中等\]  [leetcode695. 岛屿的最大面积][leetcode695.]  
 \[困难\]  [leetcode827. 最大人工岛][leetcode827.]

### BFS ###

\[中等\]  \*[leetcode 994.腐烂的橘子][leetcode 994.]  
 \[中等\]  [HJ43 迷宫问题][HJ43]  
[【算法题】走迷宫、求最少步数][Link 22]

\[中等\]  [leetcode 剑指 Offer 32 - I. 从上到下打印二叉树][leetcode _ Offer 32 - I.]  
 \[简单\]  \*[leetcode 剑指offer 32 — II.从上到下打印二叉树 II][leetcode _offer 32 _ II._ II]  
 \[中等\]  [leetcode 102. 二叉树的层序遍历][leetcode 102.]  
 \[中等\]  [leetcode 剑指offer 32 — III.从上到下打印二叉树 III][leetcode _offer 32 _ III._ III]  
[从上到下打印二叉树 I、II、III][I_II_III]

### 双指针 ###

\[简单\]  [NC61.两数之和][NC61.]

### 二叉树 ###

\[简单\] [leetcode 144. 二叉树的前序遍历][leetcode 144.]  
 \[简单\] [leetcode 194. 二叉树的中序遍历][leetcode 194.]  
 \[简单\] [leetcode 145. 二叉树的后序遍历][leetcode 145.]  
[二叉树前中后序遍历][Link 23]

### 动态规划 ###

[【算法题】机器人走迷宫][Link 24]  
[【算法题】高效的任务规划][Link 25]  
 \[中等\] [leetcode 300. 整数数组的最长严格递增子序列的长度][leetcode300]  
[【算法题】书籍叠放][Link 26]

### 链表 ###

\[中等\]  [HJ48从单向链表中删除指定值的节点][HJ48]  
leetcode160 相交链表  
剑指 Offer JZ25合并两个排序的链表

### 二进制 ###

\[简单\] [ HJ5.进制转换][HJ5.]  
[【算法题】分苹果][Link 27]  
 \[简单\]  [HJ15 求int型正整数在内存中存储时1的个数][HJ15 _int_1]  
 \[中等\]  \*[HJ33.整数与IP地址间的转换][HJ33._IP]

### 数学 ###

\[简单\]  [HJ6 质数因子][HJ6]  
[【算法题】素数之积][Link 28]  
 \[中等\]  [leetcode 204.计数质数][leetcode 204.]  
 \[入门\] [HJ7 取近似值][HJ7]

### 递归 ###

\[简单\]  [NC68.跳台阶][NC68.]

### 其他 ###

HJ25. 数据分类处理  
HJ29 字符串加解密  
剑指 Offer JZ61. 扑克牌中的顺子(类比 德州扑克问题)

leetcode 322. 零钱兑换 ，也可搜索 动态规划相关题型 （技术面试高频考点）  
火锅问题 csdn搜索

> lt （less than） 小于（<）  
> le （less than or equal to） 小于等于（<=）  
> gt （greater than） 大于（>）  
> ge （greater than or equal to）大于等于（>=）  
> eq （equal to） 等于（=）  
> ne （not equal to） 不等于（!=）

[HJ]: https://www.nowcoder.com/exam/oj/ta?tpId=37
[NC]: https://www.nowcoder.com/exam/oj
[offer_ JZ]: https://www.nowcoder.com/exam/oj/ta?page=1&tpId=13&type=13
[Link 1]: https://leetcode.cn/problemset/all/
[Java]: https://blog.csdn.net/weixin_37646636/article/details/130081037
[Java 1]: https://blog.csdn.net/weixin_37646636/article/details/132644055
[Java 2]: https://blog.csdn.net/weixin_37646636/article/details/128679549
[Java 3]: https://blog.csdn.net/weixin_37646636/article/details/128673074
[Java 4]: https://blog.csdn.net/weixin_37646636/article/details/128679627
[Java8 Stream]: https://blog.csdn.net/weixin_37646636/article/details/128667999
[Java 5]: https://blog.csdn.net/weixin_37646636/article/details/128600562
[Java _List_Map]: https://blog.csdn.net/weixin_37646636/article/details/128601266
[Java 6]: https://blog.csdn.net/weixin_37646636/article/details/128679059
[Link 2]: https://blog.csdn.net/weixin_37646636/article/details/128856219
[Link 3]: https://blog.csdn.net/weixin_37646636/article/details/120896607
[Link 4]: https://blog.csdn.net/weixin_37646636/article/details/125964928
[Link 5]: https://blog.csdn.net/weixin_37646636/article/details/128993119
[Link 6]: https://blog.csdn.net/weixin_37646636/article/details/129059907
[Link 7]: https://blog.csdn.net/weixin_37646636/article/details/130318990
[DFS _ BFS]: https://blog.csdn.net/weixin_37646636/article/details/128907610
[DFS]: https://blog.csdn.net/weixin_37646636/article/details/129073761
[HJ2]: https://blog.csdn.net/weixin_37646636/article/details/128992472
[HJ10.]: https://blog.csdn.net/weixin_37646636/article/details/128909947
[HJ23.]: https://blog.csdn.net/weixin_37646636/article/details/128917233
[HJ9]: https://blog.csdn.net/weixin_37646636/article/details/128994685
[Link 8]: https://blog.csdn.net/weixin_37646636/article/details/125959182
[HJ11]: https://blog.csdn.net/weixin_37646636/article/details/128994737
[HJ12]: https://blog.csdn.net/weixin_37646636/article/details/128994905
[HJ13]: https://blog.csdn.net/weixin_37646636/article/details/128994965
[Link 9]: https://blog.csdn.net/weixin_37646636/article/details/128758581
[HJ1]: https://blog.csdn.net/weixin_37646636/article/details/128992240
[HJ46]: https://blog.csdn.net/weixin_37646636/article/details/128995372
[Link 10]: https://blog.csdn.net/weixin_37646636/article/details/128840936
[HJ4]: https://blog.csdn.net/weixin_37646636/article/details/128992657
[Link 11]: https://blog.csdn.net/weixin_37646636/article/details/125961237
[HJ17.]: https://blog.csdn.net/weixin_37646636/article/details/128996493
[Link 12]: https://blog.csdn.net/weixin_37646636/article/details/128822371
[Link 13]: https://blog.csdn.net/weixin_37646636/article/details/128822920
[HJ20.]: https://blog.csdn.net/weixin_37646636/article/details/129000245
[NC100]: https://blog.csdn.net/weixin_37646636/article/details/129016561
[leetcode392 _ s _ t]: https://blog.csdn.net/weixin_37646636/article/details/128848769
[Link 14]: https://blog.csdn.net/weixin_37646636/article/details/126005268
[Link 15]: https://blog.csdn.net/weixin_37646636/article/details/126006244
[HJ65 _a_b]: https://blog.csdn.net/weixin_37646636/article/details/129034698
[NC149_KMP]: https://blog.csdn.net/weixin_37646636/article/details/129015749
[NC17.]: https://blog.csdn.net/weixin_37646636/article/details/129033393
[NC28.]: https://blog.csdn.net/weixin_37646636/article/details/129034228
[leetcode674.]: https://blog.csdn.net/weixin_37646636/article/details/129032921
[leetcode128]: https://blog.csdn.net/weixin_37646636/article/details/129052856
[leetcode1839]: https://blog.csdn.net/weixin_37646636/article/details/129034543
[leetcode491 _ _]: https://blog.csdn.net/weixin_37646636/article/details/129051474
[leetcode300]: https://blog.csdn.net/weixin_37646636/article/details/128821900
[Link 16]: https://blog.csdn.net/weixin_37646636/article/details/128757048
[Link 17]: https://blog.csdn.net/weixin_37646636/article/details/128787542
[Link 18]: https://blog.csdn.net/weixin_37646636/article/details/128757337
[HJ41.]: https://blog.csdn.net/weixin_37646636/article/details/128908787
[Link 19]: https://blog.csdn.net/weixin_37646636/article/details/128757882
[HJ3.]: https://blog.csdn.net/weixin_37646636/article/details/128909835
[HJ101.]: https://blog.csdn.net/weixin_37646636/article/details/129000863
[HJ68.]: https://blog.csdn.net/weixin_37646636/article/details/128960255
[HJ58 _n_k]: https://blog.csdn.net/weixin_37646636/article/details/128995699
[HJ8.]: https://blog.csdn.net/weixin_37646636/article/details/128994528
[HJ14.]: https://blog.csdn.net/weixin_37646636/article/details/128925370
[Link 20]: https://blog.csdn.net/weixin_37646636/article/details/128832212
[HJ27.]: https://blog.csdn.net/weixin_37646636/article/details/129018289
[NC37.]: https://blog.csdn.net/weixin_37646636/article/details/128926790
[JZ4]: https://blog.csdn.net/weixin_37646636/article/details/129034840
[leetcode 1614.]: https://blog.csdn.net/weixin_37646636/article/details/126005475
[NC52.]: https://blog.csdn.net/weixin_37646636/article/details/129025063
[NC175]: https://blog.csdn.net/weixin_37646636/article/details/129032083
[HJ70]: https://blog.csdn.net/weixin_37646636/article/details/129017729
[LISP]: https://blog.csdn.net/weixin_37646636/article/details/128824744
[Link 21]: https://blog.csdn.net/weixin_37646636/article/details/128825370
[239.]: https://blog.csdn.net/weixin_37646636/article/details/128787701
[leetcode _ 08.07.]: https://blog.csdn.net/weixin_37646636/article/details/126006249
[leetcode _08.08.]: https://blog.csdn.net/weixin_37646636/article/details/128961755
[leetcode 77.]: https://blog.csdn.net/weixin_37646636/article/details/128907982
[leetcode200.]: https://blog.csdn.net/weixin_37646636/article/details/129101501
[leetcode463.]: https://blog.csdn.net/weixin_37646636/article/details/129104000
[leetcode695.]: https://blog.csdn.net/weixin_37646636/article/details/129101977
[leetcode827.]: https://blog.csdn.net/weixin_37646636/article/details/129103718
[leetcode 994.]: https://blog.csdn.net/weixin_37646636/article/details/129097623
[HJ43]: https://blog.csdn.net/weixin_37646636/article/details/129099378
[Link 22]: https://blog.csdn.net/weixin_37646636/article/details/128801275
[leetcode _ Offer 32 - I.]: https://leetcode.cn/problems/cong-shang-dao-xia-da-yin-er-cha-shu-lcof/
[leetcode _offer 32 _ II._ II]: https://leetcode.cn/problems/cong-shang-dao-xia-da-yin-er-cha-shu-ii-lcof/
[leetcode 102.]: https://leetcode.cn/problems/binary-tree-level-order-traversal/
[leetcode _offer 32 _ III._ III]: https://leetcode.cn/problems/cong-shang-dao-xia-da-yin-er-cha-shu-iii-lcof/
[I_II_III]: https://blog.csdn.net/weixin_37646636/article/details/129035494
[NC61.]: https://blog.csdn.net/weixin_37646636/article/details/128909558
[leetcode 144.]: https://leetcode.cn/problems/binary-tree-preorder-traversal/
[leetcode 194.]: https://leetcode.cn/problems/binary-tree-inorder-traversal/
[leetcode 145.]: https://leetcode.cn/problems/binary-tree-postorder-traversal/
[Link 23]: https://blog.csdn.net/weixin_37646636/article/details/128945191
[Link 24]: https://blog.csdn.net/weixin_37646636/article/details/128815496
[Link 25]: https://blog.csdn.net/weixin_37646636/article/details/128816671
[Link 26]: https://blog.csdn.net/weixin_37646636/article/details/128821961
[HJ48]: https://blog.csdn.net/weixin_37646636/article/details/129086146
[HJ5.]: https://blog.csdn.net/weixin_37646636/article/details/128900556
[Link 27]: https://blog.csdn.net/weixin_37646636/article/details/128864861
[HJ15 _int_1]: https://blog.csdn.net/weixin_37646636/article/details/128995287
[HJ33._IP]: https://blog.csdn.net/weixin_37646636/article/details/128918275
[HJ6]: https://blog.csdn.net/weixin_37646636/article/details/128993073
[Link 28]: https://blog.csdn.net/weixin_37646636/article/details/128823607
[leetcode 204.]: https://blog.csdn.net/weixin_37646636/article/details/129084450
[HJ7]: https://blog.csdn.net/weixin_37646636/article/details/126006293
[NC68.]: https://blog.csdn.net/weixin_37646636/article/details/128910040