PTA 自测-4 Have Fun with Numbers

#include<iostream>
#include<string>
#include<cstring>
#include<vector>
using namespace std;
int main()
{
    int a[10] = {0},b[10] = { 0 };
    string str;
    vector<int>doublenum;//记录翻倍后的数值
    cin >> str;
    int length = str.length();
    int j = 0;
    for (int i = 0; i < length; i++)
    {
        int  num;
        num = str[i] - ‘0‘;
        a[num]++;
    }
    int carry = 0;
    for (int i = length-1; i>=0; i--)
    {
        int num = (str[i] - ‘0‘) * 2 + carry;
        if (num >=10)
            carry = 1;
        else
            carry = 0;
        int remainder = num % 10;
        b[remainder]++;
        doublenum.push_back(remainder);
    }
    if (carry == 1)
        doublenum.push_back(1);
    bool judge = true;
    for (int i = 0; i < 10; i++)
    {
        if (a[i] != b[i])
        {
            judge = false;
            break;
        }
    }
    if (judge)
    {
        cout << "Yes" << endl;
    }
    else
    {
        cout << "No" << endl;
    }
    for (int i = doublenum.size()-1; i>=0; i--)
    {
        cout << doublenum[i];
    }
    return 0;
}