C Language Basics Tutorial (v) functions (7)

Recursive invocation of 2.3 functions
Turbo C2.0 allows functions to call themselves, that is, recursive calls to functions, recursive calls can make the program concise, code compact, but at the expense of memory space for processing of the stack.
If a n! is required The value of (n's factorial) can be invoked recursively as follows:
Example 8:
#include <stdio.h>
Unsigned ling mul (int n);
int main ()
{
int m;
Puts ("Calculate n! N=?\n ");
scanf ("%d", &m); /* Keyboard input data * *
printf ("%d!=%ld\n", M, Mul (m));/* Call subroutine COMPUTE and OUTPUT * *
Getch ();
Retun 0;
}
unsigned long mul (int n)
{
unsigned long p;
if (n>1)
P=n*mul (n-1); /* Recursive call calculation n!*/
Else
p=1l;
return (p); /* Return result * *
}
Run Result:
Calculate n! N=?
Enter 5 o'clock the result is:
5!=120