题解 | #提取不重复的整数#

#include <iostream>
#include <bits/stdc++.h>
#include <map>
#include <unordered_set>
using namespace std;

int main() {
    int num;
    int val;
    unordered_set<int> hash_s;
    pair<unordered_set<int>::iterator, bool> rp;
    cin >> num;
    for(; num > 0; num /= 10){
        val = num%10;
        rp = hash_s.insert(val);
        if(rp.second){
            cout << val;
        }
        
    }

    cout << endl;
}
// 64 位输出请用 printf("%lld")