矩阵相乘

matrix.cpp

/*!
 * Matrix 
 * 已知一个矩阵A为{{3,0,4,5},{6,2,1,7},{4,1,5,8}}
 * 另一个矩阵B为{{1,4,0,3},{2,5,1,6},{0,7,4,4},{9,3,6,0}}
 * 求出A与B的乘机矩阵C[3][4]并输出出来，其中C中的每个元素C[i][j]等于∑3k=0 A[i][k]*B[k][j]。
 */
#include <iostream>
using namespace std;

void print_matrix3(int mt[3][4]) {
    int i, j;
    for(i = 0; i < 3; i++) {
        for(j = 0; j < 4; j++) {
            cout<<mt[i][j];
            if(j < 3)
                cout<<"  ";
        }
        cout<<endl;
    }
}

void print_matrix4(int mt[4][4]) {
    int i, j;
    for(i = 0; i < 4; i++) {
        for(j = 0; j < 4; j++) {
            cout<<mt[i][j];
            if(j < 3)
                cout<<"  ";
        }
        cout<<endl;
    }
}

int main(int argc, char const *argv[])
{
    int a[3][4] = {{3, 0, 4, 5},{6, 2, 1, 7},{4, 1, 5, 8}};
    int b[4][4] = {{1, 4, 0, 3},{2, 5, 1, 6},{0, 7, 4, 4},{9, 3, 6, 0}};
    int c[3][4];
    int i;
    for(i = 0; i < 3; i++) {
        int j;
        for(j = 0; j < 4; j++) {
            int k, sum = 0;
            for(k = 0; k < 4; k++) {
                sum += a[i][k]*b[k][j];
            }
            c[i][j] = sum;
        }
    }
    cout<<"Matrix A:"<<endl<<endl;
    print_matrix3(a);
    cout<<endl<<"Matrix B:"<<endl<<endl;
    print_matrix4(b);
    cout<<endl<<"Matrix C:"<<endl<<endl;
    print_matrix3(c);
    return 0;
}