题解 | #提取不重复的整数#

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

int main() {
    int a;
    cin >> a;
    unordered_set<int> uset;
    int res = 0;
    while(a > 0){
        int num = a % 10;
        a /= 10;
        if(uset.find(num) != uset.end()){
            continue;
        }
        else{
            res = res*10 + num;
            uset.insert(num);
        }
            
    }
    cout << res << endl;
}