//Citations: I read some general ideas on the Web about drawing diamonds in C
// with a given number as input. 

#include <stdio.h>

int
 main()

	{
int a, i, j, s;

	printf ("Enter the side-length of the diamond: "); //Input diamond side length
  	s = scanf ("%d", &a);

	if(a > 1)
	{//tests for valid diamond length

	 for(i = 1;i < a;i++)

	{

	for(j = a;j >= i;j--)
	printf(" ");

	 for(j = 1;j < (2 *i);j++)
	printf("*");
	printf("\n");
	}//Draws first half of diamond

	for(i = a;i >= 1;i--)
	{

	  for(j = a;j >= i;j--)
	printf(" ");

	  for(j = 1;j < (2 * i);j++)
	printf("*");
	printf("\n");

		}//Draws second half of diamond
		}
		else(printf("The argument should be a digit character greater than 1.")); //Prints error message if input is invalid.

	return 0;
	}