C++ Program For Recursive Functions

Program 1

// Program for recursion
#include<iostream>
#define clrscr() system("cls")
using namespace std;
int main()
{
     static int i=1,n;
     if(i==1)
       clrscr();
     if(i>10)
     exit(0);
     cout<<i<<endl;
     i++;
     main();
}

Program 2

// Program for recursion 1
#include<iostream>
#define clrscr() system("cls")
using namespace std;
void series(int n);
int main()
{
    int n;
    clrscr();
    cout<<"Enter a number" ;
    cin>>n;
    series(n);
}
// Recursion 
void series(int n)
{
    static int i=1;
    if(i>n)
       return;
    cout<<i<<endl;
    i++;
    series(n);

}

Program 3

// Program for factorial using recursion
#include<iostream>
#define clrscr() system("cls")
using namespace std;
int factorial(int n);
int main()
{
    int n,x;
    clrscr();
    cout<<"Enter a number" ;
    cin>>n;
    x=factorial(n);
    cout<<"\n Factorial is: "<<x;
    return 0;
}
// Recursion
int factorial(int n)
{
      static int f=1;
      if(n==0)
        return(f);
       f=f*n;
       n--;
     factorial(n);   
}

Program 4

// Program for reverse number using recursion
#include<iostream>
#define clrscr() system("cls")
using namespace std;
int reverse(int n);
int main()
{
     int n,x;
     clrscr();
     cout<<"Enter a number";
     cin>>n;
     x=reverse(n);
     cout<<"\n Reverse is: "<<x;
     if(x==n)
        cout<<"\n No is palindrom";
     else   
     cout<<"\n No is not palindrom";
}
int reverse(int n)
{
      static int s=0;
      int r;
      if(n==0)
      return s;
      
      r=n%10;
      s=s*10+r;
      n=n/10;
      reverse(n); 

}