Recursion in C

Program 1

// Implementation of recursion
#include<stdio.h>
#include<conio.h>
int main()
{
       static int i=1;
       if(i>10)
       exit(0);

     printf("%d\n",i);
     i++;  
     main();
     return 0;
}

Program 2

// Implementation of recursion
#include<stdio.h>
#include<conio.h>
int factorial(int);
int main()
{
    int n,x;
    system("cls");
    printf("Enter a number");
    scanf("%d",&n);
    x=factorial(n);
    printf("Factorial of %d is %d",n,x);
     return 0;
}
// Recursive 
int factorial(int n)
{
     static int f=1;
     if(n==0)
     return(f);

     f=f*n;
     n--;
     factorial(n);
}

Program 3

// Implementation of recursion
#include<stdio.h>
#include<conio.h>
int reverse(int);
int main()
{
    int n,x;
    system("cls");
    printf("Enter a number");
    scanf("%d",&n);
    x=reverse(n);
    printf("Reverse of %d is %d",n,x);

    if(n==x)
      printf("\n No is palindrom");
    else
    printf("\n No is not palindrom");
     return 0;
}
// Recursive 
int reverse(n)
{
    static int s=0;
    int r;
    if(n==0)
     return s;

    r=n%10;
    s=s*10+r;
    n=n/10;
    reverse(n);  
}