STL--set

C++ 中好用的STL --- set

#include<iostream>
#include<algorithm>
#include<set>
using namespace std;
int main()
{
    set<int> a;
    int n; cin >> n;
    for(int i=0;i<n;i++)
    {
        int x; cin >> x;
        a.insert(x);
    }
    for (auto x: a)
        cout << x << " ";

    return 0;
}