[prog] mutlitdimensional arrays in C

[aec]

Hi

I have a two part exercise in my C book.

1. write a program that takes a 2d array (4row 5col) and 
transposes it to a 5 row 4 col array. 

I used a function that accepts two arrays as its arguments,

----------------------------------------------------------

#include <stdio.h>

void transposeArray(int m[4][5], int n[5][4])
{
  int row, column;

 printf("\nOriginal array:\n\n");
  for (row = 0; row < 4; ++row) { // display the row
    for (column = 0; column < 5; ++column) // display the column
      printf("%5i", m[row][column]);
    printf("\n");
  }

   for (row = 0; row < 5; ++row) { // convert the array to [5][4]
    for (column = 0; column < 4; ++column)
      n[row][column] = m[column][row];
  }

  printf("\nTransposed array:\n\n");
  for (row = 0; row < 5; ++row) { // display the row
    for (column = 0; column < 4; ++column) // display the column
      printf("%5i", n[row][column]);
    printf("\n");
  }
}

int main(void)
{

  int m[4][5] = {
    {1,2,3,4,5},
    {6,7,8,9,10},
    {11,12,13,14,15},
    {16,17,18,19,20}
  };

  int n[5][4];

  transposeArray(m,n);

  return 0;
}
---------------------------------------------------------------
There is something I dont like, and that is the function does
the printing of the array, I redid this program and placed the
printing into main, and had the function return the new array
to main.

This gave me some gcc warnings but the program did compile and run
ex.8.12.c: In function `transposeArray':
ex.8.12.c:15: warning: return makes integer from pointer without a cast

I am not sure what these warnings mean, I havent done pointers yet
in the book. Also, all my types are ints, so im confused about the
"cast" in the error. 

I suspect that possibly it is the wrong way to pass an array back to main?

here is the second version that works, but gives the gcc errors:

------------------------------------------------------------------

#include <stdio.h>

int transposeArray(int m[4][5], int n[5][4])
{
  int row, column;

  for (row = 0; row < 5; ++row) { // convert the array to [5][4]
   for (column = 0; column < 4; ++column)
     n[row][column] = m[column][row];
  }
  return n;
}

int main(void)
{

  int m[4][5] = {
    {1,2,3,4,5},
    {6,7,8,9,10},
    {11,12,13,14,15},
    {16,17,18,19,20}
  };

  int n[5][4];
  int row, column;

  transposeArray(m,n);
  printf("\nOriginal array:\n\n");
   for (row = 0; row < 4; ++row) { // display the row
     for (column = 0; column < 5; ++column) // display the column
       printf("%5i", m[row][column]);
     printf("\n");
   }
  printf("\nTransposed array:\n\n");
  for (row = 0; row < 5; ++row) { // display the row
    for (column = 0; column < 4; ++column) // display the column
      printf("%5i", n[row][column]);
    printf("\n");
  }
  return 0;
}
-------------------------------------------------------------------

So, although I have technically done what the author wanted, gcc
errors bug me and Id like to know whats the cause.


-- 
Angelina Carlton