题解 | #提取不重复的整数#

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

int main() {
    int n;
    cin >> n;
    
    set<int> seen;
    int result = 0;
    
    while(n > 0) {
        int digit = n % 10;
        if(seen.find(digit) == seen.end()) {
            seen.insert(digit);
            result = result * 10 + digit;
        }
        n /= 10;
    }
    
    cout << result << endl;
    return 0;
}

import java.util.Scanner;
import java.util.HashSet;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        
        HashSet<Integer> seen = new HashSet<>();
        int result = 0;
        
        while(n > 0) {
            int digit = n % 10;
            if(!seen.contains(digit)) {
                seen.add(digit);
                result = result * 10 + digit;
            }
            n /= 10;
        }
        
        System.out.println(result);
    }
}

n = int(input())
seen = set()
result = 0

while n > 0:
    digit = n % 10
    if digit not in seen:
        seen.add(digit)
        result = result * 10 + digit
    n //= 10

print(result)