#include<stdlib.h>

unsigned int xsize,ysize;

/********************************/
void declared()
{
  int i, j;
  unsigned int k;
  int tiles[80][50];

  for(k = 0; k < 100000; k++) {

    for(i = 0; i < 80; i++) {
      for(j = 0; j < 50; j++) {
        tiles[i][j] = i + j;
      }
    }
  }
}

/********************************/
void dynamic_but_indexed()
{
  unsigned int i, j;
  unsigned int k;
  unsigned int *tiles;

  tiles = malloc(xsize * ysize * sizeof(int));

  for(k = 0; k < 100000; k++) {

    for(i = 0; i < xsize; i++) {
      for(j = 0; j < ysize; j++) {
        tiles[j + i * ysize] = i + j;
      }
    }
  }
  free(tiles);
}

/********************************/
void dynamic()
{
  unsigned int i, j;
  unsigned int k;
  unsigned int *tiles_storage;
  unsigned int **tiles;

  tiles_storage = malloc(xsize * ysize * sizeof(int));
  tiles = malloc(xsize * sizeof(int *));

  for(i = 0; i < xsize; i++) {
    tiles[i] = tiles_storage + (i * ysize);
  }

  for(k = 0; k < 100000; k++) {
 
    for(i = 0; i < xsize; i++) {
      for(j = 0; j < ysize; j++) {
        tiles[i][j] = i + j;
      }
    }
  }
  free(tiles);
  free(tiles_storage);
}

/********************************/
int main()
{
  time_t clock0, clocks;
  int ret;
  
  xsize=80;
  ysize=50;

  clock0 = clock();
  declared();
  clocks = clock();
  printf("declared = %9d\n", clocks-clock0);

  clock0 = clock();
  dynamic_but_indexed();
  clocks = clock();
  printf("indexed =  %9d\n", clocks-clock0);

  clock0 = clock();
  dynamic();
  clocks = clock();
  printf("dynamic =  %9d\n", clocks-clock0);

  return 0;
}