编写一个函数multi，实现大小两个矩阵相乘，通过主函数调用该函数，并输出结果，要求使用函数、指针

下面是使用函数、指针实现两个矩阵相乘的程序：

#include <stdio.h>
#include <stdlib.h>

void multi(int **matrix1, int **matrix2, int **result, int row1, int col1, int col2)
{
    int i, j, k;
    for (i = 0; i < row1; i++) {
        for (j = 0; j < col2; j++) {
            result[i][j] = 0;
            for (k = 0; k < col1; k++) {
                result[i][j] += matrix1[i][k] * matrix2[k][j];
            }
        }
    }
}

int main()
{
    int i, j;
    int row1 = 2, col1 = 3, row2 = 3, col2 = 2;
    int **matrix1, **matrix2, **result;

    //allocate memory for matrix1
    matrix1 = (int **)malloc(row1 * sizeof(int *));
    for (i = 0; i < row1; i++) {
        matrix1[i] = (int *)malloc(col1 * sizeof(int));
    }

    //allocate memory for matrix2
    matrix2 = (int **)malloc(row2 * sizeof(int *));
    for (i = 0; i < row2; i++) {
        matrix2[i] = (int *)malloc(col2 * sizeof(int));
    }

    //allocate memory for result
    result = (int **)malloc(row1 * sizeof(int *));
    for (i = 0; i < row1; i++) {
        result[i] = (int *)malloc(col2 * sizeof(int));
    }

    //initialize matrix1
    printf("Enter elements for matrix1:\n");
    for (i = 0; i < row1; i++) {
        for (j = 0; j < col1; j++) {
            scanf("%d", &matrix1[i][j]);
        }
    }

    //initialize matrix2
    printf("Enter elements for matrix2:\n");
    for (i = 0; i < row2; i++) {
        for (j = 0; j < col2; j++) {
            scanf("%d", &matrix2[i][j]);
        }
    }

    //multiply matrix1 and matrix2
    multi(matrix1, matrix2, result, row1, col1, col2);

    //print the result matrix
    printf("The result is:\n");
    for (i = 0; i < row1; i++) {
        for (j = 0; j < col2; j++) {
            printf("%d ", result[i][j]);
        }
        printf("\n");
    }

    //free memory
    for (i = 0; i < row1; i++) {
        free(matrix1[i]);
    }
    free(matrix1);
    for (i = 0; i < row2; i++) {
        free(matrix2[i]);
    }
    free(matrix2);
    for (i = 0; i < row1; i++) {
        free(result[i]);
    }
    free(result);

    return 0;
}

函数multi接收三个矩阵和矩阵的行列数，通过指针实现矩阵相乘操作。在主函数中，先动态分配内存空间并初始化两个矩阵，然后调用multi函数进行相乘操作，最后输出结果并释放内存。