题解 | #特殊乘法#

#include <iostream>

using namespace std;

int main() {
    string str1, str2;
    int sum = 0;
    char a = '0';
    while (cin >> str1 >> str2) { //用cin
        for (int i = 0; i < str1.size(); i++) {
            for (int j = 0; j < str2.size(); j++) {
                //char a='0';
                // printf("%d",a);//注意此处字符转换，0的ASCII码不是0,是48
                sum = sum + ((int)str1[i] - (int)a) * ((int)str2[j] - (int)a);

            }
        }
        cout << sum << endl;
    }

}