L1-048. 矩阵A乘以B

L1-048. 矩阵A乘以B

问题描述

代码

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int m1,n1,m2,n2;
    cin >> m1 >> n1;
    int a[m1][n1];
    for (int i = 0; i < m1; i++) {
        for (int j = 0; j < n1; j++) {
            cin >> a[i][j];
        }
    }
    cin >> m2 >> n2;
    if (n1 != m2) {
        cout << "Error: " << n1 << " != " << m2;
        return 0;
    }
    int b[m2][n2];
    int c[m1][n2];
    for (int i = 0; i < m1; i++) {
        for (int j = 0; j < n2; j++) {
            c[i][j] = 0;
        }
    }
    for (int i = 0; i < m2; i++) {
        for (int j = 0; j < n2; j++) {
            cin >> b[i][j];
        }
    }
    for (int i = 0; i < m1; i++) 
        for (int j = 0; j < n2; j++) 
            for (int k = 0; k < m2; k++) { 
                c[i][j] += a[i][k] * b[k][j]; 
            }
    cout << m1 << " " << n2 << endl;
    for (int i = 0; i < m1; i++) {
        for (int j = 0; j < n2; j++) {
            cout << c[i][j];
            if (j != n2 - 1) {
                cout << " ";
            }
        }
        cout << endl;
    }
}