C program to draw pascals triangle

#include <stdio.h>

long factorial(int);

int main()
{
   int i, n, c;

   printf("Enter the number of rows you wish to see in pascal triangle\n");
   scanf("%d",&n);

   for (i = 0; i < n; i++)
   {
      for (c = 0; c <= (n - i - 2); c++)
         printf(" ");

      for (c = 0 ; c <= i; c++)
         printf("%ld ",factorial(i)/(factorial(c)*factorial(i-c)));

      printf("\n");
   }

   return 0;
}

long factorial(int n)
{
   int c;
   long result = 1;

   for (c = 1; c <= n; c++)
         result = result*c;

   return result;
}