Update Factorial.c

Author: gouravthakur39

Factorial.c

@@ -1,13 +1,15 @@
-include <stdio.h>
+#include <stdio.h>
 int main()
 {
     int n, i;
     unsigned long long factorial = 1;
+    //unsigned long long is the same as unsigned long long int. 
+    //Its size is platform-dependent, but guaranteed by the C standard (ISO C99) to be at least 64 bits. 
 
     printf("Enter a number: ");
     scanf("%d",&n);
 
-    // SHow error if number is less than 100
+    // Show error if number is less than 0
     if (n < 0)
         printf("Error! Factorial of a negative number doesn't exist.");