Program
/* File: countdown.c
*
* A very simple recursive function.
*/
#include <stdio.h>
void Countdown (int) ;
main()
{
int n ;
printf("Engaging the auto-destruct sequence\n") ;
printf("Enter number of seconds to auto-destruct: ") ;
scanf("%d", &n) ;
printf("Counting down from %d\n", n) ;
Countdown(n) ;
}
/* This is a simple recursive function
*/
void Countdown (int k)
{
if (k == 0)
{
printf("KABOOM!!!\n") ;
}
else
{
printf(" %d seconds to auto-destruct\n", k) ;
Countdown (k - 1) ;
}
}
Output
lassie% cc201 countdown.c
lassie%
lassie% a.out
Engaging the auto-destruct sequence
Enter number of seconds to auto-destruct: 9
Counting down from 9
9 seconds to auto-destruct
8 seconds to auto-destruct
7 seconds to auto-destruct
6 seconds to auto-destruct
5 seconds to auto-destruct
4 seconds to auto-destruct
3 seconds to auto-destruct
2 seconds to auto-destruct
1 seconds to auto-destruct
KABOOM!!!
lassie%
lassie% a.out
Engaging the auto-destruct sequence
Enter number of seconds to auto-destruct: 17
Counting down from 17
17 seconds to auto-destruct
16 seconds to auto-destruct
15 seconds to auto-destruct
14 seconds to auto-destruct
13 seconds to auto-destruct
12 seconds to auto-destruct
11 seconds to auto-destruct
10 seconds to auto-destruct
9 seconds to auto-destruct
8 seconds to auto-destruct
7 seconds to auto-destruct
6 seconds to auto-destruct
5 seconds to auto-destruct
4 seconds to auto-destruct
3 seconds to auto-destruct
2 seconds to auto-destruct
1 seconds to auto-destruct
KABOOM!!!
lassie%