1. Code

#include <iostream>

using namespace std;

int main(void) {
    int A,B,C, mul;
    int cnts[10] = {0,};
    cin >> A >> B >> C;

    mul = A*B*C;
    while(mul>0) {
        cnts[mul%10]++;
        mul /= 10;
    }
    
    for (int i=0 ; i<10 ; i++) {
        cout << cnts[i] << "\n";
    } 
    return 0;
}

2. Result

        Runtime : 0 ms, Memory usage : 2016 KB
        (Runtime can be different by a system even if it is a same code.)

Check out the my GitHub repo for more info on the code. If you have questions, you can leave a reply on this post.