vector的初始化

vector初始化方法

#include <iostream>
#include<vector>
using namespace std;

int main()
{
    //vector的初始化方法

    //1.初始化一个空的vector,并且添加一个元素
    vector<int> first;
    first.insert(first.begin(),1);
    cout<<first[0]<<endl;

    //2.指明vector的所包含的元素个数并且赋初值
    vector<int> second(4,100);
    cout<<second[3]<<endl;

    //3.利用第二个初始化第三个
    vector<int> third(second.begin(),second.end());
    cout<<third[0]<<" "<<third[3]<<endl;

    //4.复制第三个vector
    vector<int> fourth(third);
    cout<<fourth[0]<<" "<<fourth[3]<<endl;

    //5.利用数组进行初始化
    int myints[4]={16,2,77,29};
    vector<int> fifth(myints,myints+4);
    for(int i=0;i<fifth.size();i++)
        cout<<fifth[i]<<" ";
    
    return 0;
}