[PAT-A] 1023 Have Fun with Numbers

Java

package PAT_A1023_Have_Fun_with_Numbers;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.*;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String s = br.readLine();

        List<Integer> a = new ArrayList<>();
        for (int i = s.length() - 1; i >= 0; i--) {
            a.add(s.charAt(i) - '0');
        }

        List<Integer> b = new ArrayList<>();
        int t = 0;
        for (Integer integer : a) {
            int sum = integer + integer + t;
            b.add(sum % 10);
            t = sum / 10;
        }
        if (t != 0) {
            b.add(t);
        }

        List<Integer> c = new ArrayList<>(b);
        Collections.sort(a);
        Collections.sort(c);
        if (a.equals(c)) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }

        for (int i = b.size() - 1; i >= 0; i--) {
            System.out.print(b.get(i));
        }
    }
}

C++

#include <iostream>
#include <cstring>
#include <algorithm>
#include <vector>

using namespace std;

string s;
vector<int> a;

int main() {
    cin >> s;
    for (int i = s.size() - 1; i >= 0; i--) a.push_back(s[i] - '0');

    vector<int> b;
    int t = 0;
    for (int i = 0; i < a.size(); i++) {
        int s = a[i] + a[i] + t;
        b.push_back(s % 10);
        t = s / 10;
    }
    if (t) b.push_back(t);

    vector<int> c = b;
    sort(a.begin(), a.end());
    sort(c.begin(), c.end());
    if (a == c) puts("Yes");
    else puts("No");

    for (int i = b.size() - 1; i >= 0; i--) cout << b[i];

    return 0;
}