找出数组中重复的元素 n个数（每个数的取值范围是1到n-1）

https://www.acwing.com/solution/content/707/ 把每个数放到它原本的位置上去O(n),O(1),数组发生了改变

https://www.acwing.com/solution/content/693/ 抽屉原理二分法，O(nlogn),O(1),数组没发生了改变

计数数组 O(n),O(n),数组没发生改变

只有1个数只出现了一次，其余的数都出现了2次

image-20211226162549305

异或

只有1个数只出现了一次，其余的数都出现了2次

image-20211226163302476

先异或所有的，得到的结果就是x^y,因为它不等于0，所以二进制数一定有1位为1，设这一位数为k

而x、y在这位数上一定不同，把这位数上为1的分为一类，这一类中包含x或y的一个，异或这一类得出x

再x^x^y=y

在一个数组中除了一个数字只出现一次之外，其他数字都出现了三次。

image-20211226165933847

image-20211226165950593

🗡☞offer

https://blog.csdn.net/qq_30277239/category_8713779_2.html

算法提高课

https://blog.csdn.net/qq_30277239/category_9672147_2.html

大厂笔试

网易2021

https://www.nowcoder.com/questionTerminal/592a069811044d3fadb94c6c55d7b4f2

Comparable和Comparator区别是什么？

image-20211125164725866

http/2相比http/1.1有什么新特性？

image-20211125164914995

image-20211125164925059

STL

map

红黑树

在map内部所有的数据都是有序的

1
2
3
4
5
6

map<int,int> m1;
for(auto x:m1){
    if(x.second==1){
        cout<<m2[x.first]<<endl;
    }
}

DP

https://www.acwing.coml/blog/content/7459/

https://oi-wiki.org/string/trie/

https://space.bilibili.com/517494241?spm_id_from=333.788.b_765f7570696e666f.2

上下左右走

最长上升子序列模型

背包模型

状态机模型

连通性状态压缩dp

集合类状态压缩

区间dp

树形dp

image-20211229205616378

数位dp

单调队列优化dp

斜率优化dp

搜索

Flood Fill

https://blog.csdn.net/weixin_42979819/article/details/104020930 https://blog.csdn.net/weixin_42638946/article/details/114854833

BFS综合

https://blog.csdn.net/weixin_42638946/article/details/114905541

最短路模型

https://www.acwing.com/solution/content/2078/ https://blog.csdn.net/weixin_43798170/article/details/113819433 https://www.acwing.com/problem/content/190/ https://blog.csdn.net/qq_30277239/article/details/104680308

多源bfs

https://www.acwing.com/problem/content/175/

最小步数模型

https://www.acwing.com/problem/content/847/ https://www.acwing.com/problem/content/1109/

双端队列广搜

https://www.acwing.com/problem/content/177/

A*

https://www.acwing.com/problem/content/180/ https://www.acwing.com/problem/content/181/

DFS综合

https://blog.csdn.net/weixin_42638946/article/details/114993465

DFS连通性模型

https://www.cnblogs.com/WAsbry/p/12836812.html https://blog.csdn.net/qq_45927003/article/details/112845344

DFS搜索顺序

https://blog.csdn.net/weixin_45480785/article/details/113802964

https://blog.csdn.net/m0_46656833/article/details/116027525

https://blog.csdn.net/qq_30277239/article/details/104799213

DFS剪枝与优化

https://www.acwing.com/problem/content/168/ https://www.acwing.com/problem/content/167/ https://www.acwing.com/problem/content/169/ https://www.acwing.com/problem/content/170/

迭代加深

https://www.acwing.com/problem/content/172/

双向dfs

https://www.acwing.com/problem/content/173/

IDA*

https://www.acwing.com/problem/content/182/ https://www.acwing.com/problem/content/183/

基础知识

双指针算法

https://blog.csdn.net/suxiaorui/article/details/106222438 https://blog.csdn.net/qq_30277239/article/details/100877076

位运算

https://www.acwing.com/problem/content/description/92/ https://blog.csdn.net/weixin_43681549/article/details/113872488

离散化

https://blog.csdn.net/weixin_43681549/article/details/113872897

RMQ

https://blog.csdn.net/qq_46105170/article/details/119861243

区间合并

https://www.acwing.com/solution/content/2615/

数据结构

单链表

https://www.acwing.com/problem/content/828/

双链表

https://www.acwing.com/problem/content/829/

栈

https://www.cnblogs.com/ITduange/p/14457644.html

队列

https://www.cnblogs.com/ITduange/p/14457676.html

单调栈

https://blog.csdn.net/YSA__/article/details/107499102

单调队列

https://www.acwing.com/problem/content/156/

KMP

https://www.acwing.com/solution/content/14666/

Trie

https://www.acwing.com/problem/content/145/

https://www.acwing.com/solution/content/14695/

并查集

https://www.acwing.com/problem/content/description/838/

https://blog.csdn.net/YSA__/article/details/107696344

https://blog.csdn.net/qq_52358098/article/details/114220210

https://blog.csdn.net/qq_52358098/article/details/114221482

https://www.acwing.com/problem/content/239/

https://www.acwing.com/problem/content/240/

https://www.acwing.com/problem/content/241/

https://www.acwing.com/problem/content/242/

堆

https://www.acwing.com/problem/content/108/

https://www.acwing.com/problem/content/840/

https://blog.csdn.net/YSA__/article/details/108416108

哈希表

https://blog.csdn.net/YSA__/article/details/108437830

https://www.acwing.com/solution/content/24738/

树状数组

https://www.acwing.com/problem/content/243/

https://www.acwing.com/problem/content/244/

https://www.acwing.com/problem/content/248/

https://www.acwing.com/problem/content/245/

线段树

https://www.acwing.com/problem/content/244/

https://www.acwing.com/problem/content/246/

https://www.acwing.com/problem/content/247/

https://www.acwing.com/problem/content/249/

https://blog.csdn.net/zzq0523/article/details/113183214

https://blog.csdn.net/qq_52358098/article/details/117306705

可持久化数据结构

https://www.acwing.com/problem/content/257/

https://www.acwing.com/problem/content/258/

平衡树

https://www.acwing.com/problem/content/255/

https://www.acwing.com/problem/content/267/

AC自动机

https://blog.csdn.net/weixin_43798170/article/details/114273860

https://www.acwing.com/solution/content/56098/

https://www.acwing.com/solution/content/7760/

图论

单源最短路初级

https://www.acwing.com/solution/content/9306/

https://www.acwing.com/problem/content/851/

https://www.acwing.com/problem/content/852/

https://www.acwing.com/problem/content/853/

https://www.acwing.com/problem/content/855/

https://blog.csdn.net/qq_44791484/article/details/116587679

https://www.acwing.com/problem/content/1129/

https://blog.csdn.net/qq_30277239/article/details/106104598

https://blog.csdn.net/qq_30277239/article/details/106106290

https://www.acwing.com/problem/content/922/

https://www.acwing.com/problem/content/905/

单源最短路中级

https://www.acwing.com/problem/content/342/

https://www.acwing.com/problem/content/343/

https://www.acwing.com/problem/content/344/

https://blog.csdn.net/qq_30277239/article/details/106317639

单源最短路高级

https://blog.csdn.net/qq_30277239/article/details/106864304

https://www.acwing.com/problem/content/385/

https://blog.csdn.net/qq_30277239/article/details/106819891

https://blog.csdn.net/qq_30277239/article/details/106743915

负环

https://blog.csdn.net/qq_30277239/article/details/101060037

https://www.acwing.com/problem/content/363/

https://blog.csdn.net/qq_30277239/article/details/108330375

https://blog.csdn.net/qq_30277239/article/details/108436287

差分约束

https://www.acwing.com/problem/content/364/

https://www.acwing.com/problem/content/395/

https://blog.csdn.net/qq_30277239/article/details/108966877 牛

https://blog.csdn.net/qq_30277239/article/details/109248159

Floyd

https://blog.csdn.net/qq_30277239/article/details/101062266

https://www.acwing.com/problem/content/345/

https://www.acwing.com/problem/content/346/

https://www.acwing.com/problem/content/347/

https://blog.csdn.net/qq_30277239/article/details/107301496

最小生成树初级

最基础的prim和kruskal

https://blog.csdn.net/qq_30277239/article/details/101064096

https://blog.csdn.net/qq_30277239/article/details/101066119

较简单

https://blog.csdn.net/qq_30277239/article/details/107891523

https://blog.csdn.net/qq_30277239/article/details/107898613

小技巧（最小生成树的最大边；有一些边是必选的，就输入时处理；点阵连通，不用构图，直接用性质

https://blog.csdn.net/qq_30277239/article/details/107899568

https://blog.csdn.net/qq_30277239/article/details/107899955

https://blog.csdn.net/qq_30277239/article/details/107900698

最小生成树中级

https://www.acwing.com/problem/content/348/

https://blog.csdn.net/qq_30277239/article/details/108184284

https://blog.csdn.net/qq_30277239/article/details/108038467

https://blog.csdn.net/qq_30277239/article/details/108033213

https://blog.csdn.net/qq_30277239/article/details/108190012

欧拉回路

https://blog.csdn.net/weixin_42638946/article/details/115432734

拓扑排序

https://blog.csdn.net/weixin_42638946/article/details/115442368

最近公共祖先

https://blog.csdn.net/weixin_42638946/article/details/115321434

有向图强连通分量

https://blog.csdn.net/weixin_42638946/article/details/115385877 牛

https://blog.csdn.net/qq_30277239/article/details/118683637

https://blog.csdn.net/qq_30277239/article/details/118880405

https://www.acwing.com/problem/content/370/

无向图双连通分量

https://blog.csdn.net/weixin_42638946/article/details/115413418 牛

https://www.acwing.com/problem/content/397/

https://www.acwing.com/problem/content/398/

染色体法 and匈牙利算法 二分图

https://blog.csdn.net/weixin_42638946/article/details/115422539

数学知识

质数

https://blog.csdn.net/weixin_42638946/article/details/115703334

约数

https://blog.csdn.net/weixin_42638946/article/details/115706223

快速幂

https://blog.csdn.net/weixin_42638946/article/details/115716902

欧拉函数

https://blog.csdn.net/weixin_42638946/article/details/115708467

扩展欧几里得算法

https://blog.csdn.net/weixin_42638946/article/details/115719532

中国剩余定理

https://blog.csdn.net/weixin_42638946/article/details/115728340

矩阵乘法

https://blog.csdn.net/weixin_42638946/article/details/115872469

高斯消元

https://blog.csdn.net/weixin_42638946/article/details/115736209

组合数

https://blog.csdn.net/weixin_42638946/article/details/115751984

容斥原理

https://blog.csdn.net/weixin_42638946/article/details/115764996

概率与数学期望

https://www.acwing.com/problem/content/219/

https://www.acwing.com/problem/content/220/

模拟退火

https://blog.csdn.net/weixin_42638946/article/details/120817011

博弈论

https://blog.csdn.net/weixin_42638946/article/details/115772126