#include "iostream"
#include "vector"
#include "list"
#include "unordered_map"
#include "map"
#include "unordered_set"  //哈希表
#include "string"
#include "queue"
#include "algorithm"
using namespace std;

#define x first
#define y second
typedef pair<int,int> PII;


int main()
{   
    cout<<"=========vector========="<<endl;
    //=============================vector=============================
    vector<int> vec;
    vec.push_back(1);  //尾部插入数字
    vec.push_back(2);
    vec.push_back(3);
    cout<<vec.front()<<endl;         //返回第一个数据
    vec.insert(vec.begin()+2,66);    //第2个元素后面插入
    vec.erase(vec.begin()+2);        //删除第三个元素   1 2 3 
    vec.pop_back();                  //删除最后一个元素
    //vec.clear();  //清空vec

    reverse(vec.begin(),vec.end());   //逆序   3 2 1
    sort(vec.begin(),vec.end());      //排序 从小到大 1 2 3  
    cout<<"vector大小"<<vec.size()<<endl;

    vector<int>::iterator it;
    for(it=vec.begin();it!=vec.end();it++)
        cout<<*it<<endl;



    cout<<"=======string==========="<<endl;
    //==========================string================================
    string str="hausthaust";
    int cnt=count(str.begin(),str.end(),'h');
    cout<<"h的数量:"<<cnt<<endl;
    sort(str.begin(),str.end()); 
    cout<<str<<endl;

    //s.substr(pos, n)    从pos开始的n个字符的拷贝。



    cout<<"=========pair========="<<endl;
    //==================================pair=============================
    //pair一般用来存坐标

    PII p[10];

    for(int i=0;i<5;i++) p[i].x=p[i].y=100-i;

    for(int i=0;i<5;i++) cout<<p[i].x<<" "<<p[i].y<<endl;



    cout<<"=========map========="<<endl;
    //==================================map=============================
    map<int,string> m;
    m[1]="hello";
    m[2]="world";
    m.insert({3,"dxh"});
    cout<<m.size()<<endl;
    cout<<m[1]<<endl;
    cout<<m[2]<<endl;
    cout<<m[3]<<endl;
    for(int i=1;i<=m.size();i++) cout<<m[i]<<" ";
    return 0;
}