Diamond Star Pattern

#include <stdio.h>
int
main (void)
{
  int n;
  printf ("Enter the number of rows\n");
  scanf ("%d", &n);
  int spaces = n - 1;
  int stars = 1;
  for (int i = 1; i <= n; i++)
    {
      for (int j = 1; j <= spaces; j++)
	{
	  printf (" ");
	}
      for (int k = 1; k <= stars; k++)
	{
	  printf ("*");
	}
      if (spaces > i)
	{
	  spaces = spaces - 1;
	  stars = stars + 2;
	}
      if (spaces < i)
	{
	  spaces = spaces + 1;
	  stars = stars - 2;
	}
      printf ("\n");
    }
  return 0;
}

Enter the number of rows
20
                   *
                  ***
                 *****
                *******
               *********
              ***********
             *************
            ***************
           *****************
          *******************
          *******************
           *****************
            ***************
             *************
              ***********
               *********
                *******
                 *****
                  ***
                   *