Submission

Score: 100

User: iij

Problemset: I.Quick Math

Language: cpp

Time: 0.002 second

Submitted On: 2025-10-22 17:09:20

#include <iostream>
#include <vector>

using namespace std;
int main() {
    string a, b;
    cin >> a >> b;

    if (a == "0" || b == "0") {
        cout << 0;
        return 0;
    }

    vector<int> ans(9000, -1);
    for (int i = 0; i < a.length(); i++) {
        for (int j = 0; j < b.length(); j++) {
            if (ans[i + j] == -1) ans[i + j] = 0;
            ans[i + j] += (a[i] - '0') * (b[j] - '0');
        }
    }

    for (int i = ans.size() - 1; i > 0; i--) {
        ans[i - 1] += ans[i] / 10;
        ans[i] %= 10;
    }

    for (auto i : ans) if (i != -1) cout << i;
}