Part-2 Recursion in c#

6) print the even & odd numbers in separate line for n:

i/p:

20

o/p:

2 4 6 8 10 12 14 16 18 20

1 3 5 7 9 11 13 15 17 19 

Solution:

using System;

class Program {

  public static void printEven(int i,int n){

      if(i>n)  return;      //condition to break the recursion 

       if(i!=0)  Console.Write("{0} ",i);  

      printEven(i+=2,n);       

  }

  public static void printOdd(int i,int n){

      if(i>n) return;   //condition to break the recursion 

      Console.Write("{0} ",i);

      printEven(i+=2,n);    

  }

  static void Main() {

    printEven(0,20);

    Console.WriteLine("");

    printOdd(1,20);

  }

} 

7) print the number is prime or not:

i/p:

26

o/p:

Prime Number bcz its divisible by 2

i/p:

23

o/p:

Non Prime Number

Solution:

using System;

class Program {

  public static void printPrime(int i,int n)

  {

      if(i>=n)

      {

        Console.WriteLine("Non Prime number");

        return;

      }

        if(n%i==0 && i!=1){

            Console.WriteLine("Prime number Bcz divisible by {0}",i);

            return;

        }

        printPrime(i+=1,n);        

  }

  static void Main() {

    printPrime(1,27);

  }

}

8)  print the number is prime or not:

i/p:

MADAM

o/p:

Its Palindrome

i/p:

TATOO

o/p:

Its Not Palindrome

Solution:

using System;

class Program {

  public static void checkPalindrome(char[] ch,int i,int j)

  {

      if(i>=j) { Console.Write("Its Palindrome");  return;  }

      if(ch[i]==ch[j]) { checkPalindrome(ch,i+=1,j-=1);   }

      else{  Console.Write("Its not Palindrome");  return;   }  

  }

  static void Main() {

      string s="MADAM";

      char[] ch=s.ToCharArray();

    checkPalindrome(ch,0,s.Length-1);

  }

}

9)  print the factorial of the number n:

i/p:

5

o/p:

120

i/p:

3

o/p:

6

Solution:

using System;

class Program {

 public static void printFactorialOfNumber(int fact,int n)

 {

     if(n==0) {    Console.Write(fact);   return; }

     printFactorialOfNumber(fact*n,n-=1); 

 }

  static void Main() {

      int fact=3;

    printFactorialOfNumber(fact,fact-1);

  }

}

10) print the fibonnaci series of the number n:

i/p:

6

o/p:

0 1 1 2 3 5

Solution:

using System;

class Program {

 public static void printFibonacciSeries(int n,int i,int j)

 {

     if(n==0){ return; }

     if(i==0){ Console.Write("{0} ", i); }

      Console.Write("{0} ", j);

     int t=j;

     j=i+j;

     i=t;

     printFibonacciSeries(n-=1,i,j);

 } 

  static void Main() {

      int fib=10;

    printFibonacciSeries(fib-1,0,1);

  }

}