题解 | 特殊乘法

#include <iostream>
#include <string>
#include <cstdio>
#include <algorithm>
#include <cmath>

using namespace std;

//利用字符串得到两个数的位数
string a, b;

int main() {
    cin >> a >> b;
    int alen = a.length(), blen = b.length();
    int fa = stoi(a), fb = stoi(b);//转化为整型
    int tempa = 0, tempb = 0;
    for (int i = 0; i < alen; i++) {
        tempa += fa % 10;
        fa = fa / 10;
    }
    for (int i = 0; i < blen; i++) {
        tempb += fb % 10;
        fb = fb / 10;
    }
    cout << tempa * tempb << endl;
}