题解 | #提取不重复的整数#

#include <unordered_map>
#include <iostream>
using namespace std;

int main() {
   int num;
   int ans = 0;
   unordered_map<int, int> hashtable;

   cin>>num;
   while(num!=0){
        
        if(hashtable.count(num%10) == 0){
            ans = ans*10 + num%10;
            hashtable[num%10]++;
        }
        num = num/10;
   }

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