C++ 计算三位数加法进位次数

#include <iostream>
using namespace std;

int main() {
    int a, b;
    while(cin >> a >> b && (a != 0 || b != 0)) {
        int count = 0;
        int carry = 0;
        while(a > 0 || b > 0) {
            int digit_a = a % 10;
            int digit_b = b % 10;
            int sum = digit_a + digit_b + carry;
            if(sum >= 10) {
                count++;
                carry = 1;
            } else {
                carry = 0;
            }
            a /= 10;
            b /= 10;
        }
        cout << count << endl;
    }
    return 0;
}