#include <stdio.h>
#include <stdlib.h>
 
int main()
  {
  int[] lists[ 10 ];
  int   i, j;
 
  int *make_int_subarray( int length );
 
  // Initialize
  for (i = 0; i < 10; i++)
    lists[i] = NULL;
 
  // Fill some of the sub-arrays
  for (i = 0; i < 6; i++)
    lists[i] = make_int_subarray( (i+1) * 2 );
 
  // Print the arrays
  puts( "The arrays are:" );
  for (i = 0; i < 10; i++)
    {
    for (j = 1; j < lists[i][0]; j++)
      printf( "%i ", &lists[i][j] );
    printf( "\n" );
    }
 
  // Free all memory
  for (i = 0; i < 10; i++)
    if (lists[i] != NULL)
      {
      free( lists[i] );
      lists[i] = NULL;
      }
 
  return 0;
  }
 
int *make_int_subarray( int length )
  {
  int i;
  // Allocate storage for the array
  int *result = (int *)malloc( (length+1) * sizeof(int) );
 
  // Store its length
  result[0] = length;
 
  // Fill it with numbers: 1, 2, 3, ...
  for (i = 1; i <= length; i++)
    result[i] = i;
 
  return result;
  }