vector set_union() /set_intersection【集合合并/交集】

#include<iostream>#include<algorithm>#include<vector>#include<map>#include<set>#define ALL(x) x,x+5#define INS(x) x.begin()using namespace std;int f[5]={5,10,15,20,25};int s[5]={50,40,30,20,10};void put(){    for(int i=0;i<5;i++)        cout<<f[i]<<" ";    cout<<endl;    for(int i=0;i<5;i++)        cout<<s[i]<<" ";    cout<<endl;}int main(){    vector<int> v(10);   //并不知道开多大的空间  最后可以用    v.resize(it-INS(v)); 收场    vector<int>::iterator it;    sort(f,f+5);    sort(s,s+5);    put(); //输出当前排好序的两个数组    //it=set_union(ALL(f),ALL(s),INS(v)); // 5 10 15 20 25 30 40 50 0 0    it=set_intersection(ALL(f),ALL(s),INS(v));  //10 20 0 0 0 0 0 0 0 0    v.resize(it-INS(v));  //改变v容器的大小    cout<<v.size()<<endl;    for(it=v.begin();it!=v.end();++it)  cout<<*it<<" ";    cout<<endl;    return 0;}