set vector 删除重复元素

#include <iostream>
#include<cstdio>
#include <vector>
#include <set>
#include <iterator>
using namespace std;

int main()
{
    set<int>s;
    cout << "please input the number of vector's element " << endl;
    int n;
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        int temp;
        cin >> temp;
        s.insert(temp);
    }
    vector<int>v;
    insert_iterator<vector<int> > in_it(v, v.begin());
    copy(s.begin(), s.end(), in_it);
    printf("%d\n",v.size());
    for (vector<int>::iterator it = v.begin(); it != v.end(); it++)
    {
        cout << *it << " ";
    }
    return 0;
}