题解 | #特殊乘法#

#include <cstdio>
#include <string>
using namespace std;
int main() {
    int arr1;
    int arr2;
    while (scanf("%d%d", &arr1, &arr2) != EOF) {
        int sum = 0;
        string str2 = to_string(arr2);
        string str1 = to_string(arr1);
        for (int i = 0; i < str1.size(); i++) {
            for (int j = 0; j < str2.size(); j++) {
                sum = sum + (str1[i] - '0') * (str2[j] - '0');
            }
        }
        printf("%d", sum);
    }
}