#include <stdio.h>

#define M 3
#define N 4
#define P 3

void fun(int a[M][N], int b[N][P], int m, int p, int n)//定义函数fun 
{
	printf("m: %d, p: %d, n: %d\n", m, p, n);
	
	int c[M][P]={0};
	int i, j, k;
	for(i = 0; i < m; i++)
	{
		for(j = 0; j < n; j++)
		{
			for(k = 0; k < p; k++)
			{				
				c[i][j] += a[i][k] * b[k][j];//计算相乘后矩阵各个值 
			}			
		}
	}

	for(i = 0; i < m; i++)
	{
		for(j = 0; j < n; j++)
		{
			printf("c[%d][%d]: %3d ", i, j, c[i][j]);
		}
		printf("\n");
	}						
}

int main()
{
	int a[M][N] = {{1,2,3,4}, {5,6,7,8}, {9,10,11,12}}; //2行4列
	int b[N][P] = {{1,2},{3,4},{5,6},{7,8}}; //4行2列	
	
	fun(a, b, M, N, P);//调用矩阵相乘函数fun 
	
	return 0;	 
}

运行结果：