[백준] 2740 행렬 곱셈

2740번: 행렬 곱셈

 

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풀이

[프로그래머스] 행렬의 곱셈과 동일한 문제이다.

코드

#include <iostream>
#include <vector>
using namespace std;

int n1, n2, m1, m2;
vector<vector<int>> arr1, arr2;

void solve() {
    int n = arr1.size(), m = arr2[0].size();
    vector<vector<int>> result(n, vector<int>(m));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            int sum = 0;
            for (int k = 0; k < arr1[i].size(); k++) {
                sum += (arr1[i][k] * arr2[k][j]);
            }
            result[i][j] = sum;
        }
    }

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++)
            cout << result[i][j] << ' ';
        cout << '\n';
    }
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    cin >> n1 >> m1;
    arr1 = vector<vector<int>>(n1, vector<int>(m1));
    for (int i = 0; i < n1; i++) for (int j = 0; j < m1; j++) cin >> arr1[i][j];
    cin >> n2 >> m2;
    arr2 = vector<vector<int>>(n2, vector<int>(m2));
    for (int i = 0; i < n2; i++) for (int j = 0; j < m2; j++) cin >> arr2[i][j];
    solve();
    return 0;
}