求一个4*4矩阵的转置，并且要输出原来的矩阵

#include "stdio.h"#define M 4#define N 4void main(){  int i, k;  int a[M][N] = {{1, 2, 3, 4}, { 5, 6, 7, 8,}, { 9, 10, 11, 12}, {13, 14, 15, 16}};  int b[M][N];    for ( i = 0; i < M; i++)  for (k = 0; k < N; k++)  b[i][k] = a[k][i];    printf ("原来的矩阵\n");  for (i = 0; i < M; i++)  {    for ( k = 0; k < N; k++)printf("%5d", a[i][k]);    printf ("\n");  }      printf ("转换后的矩阵\n");    for (i = 0; i < M; i++)  {     for ( k = 0; k < N; k++)printf ("%5d", b[i][k]);   printf ("\n");  }}