Programs using Recursive Function

Recursive Function is a functtion which calls itself.Every recursive function must have a base condition to stop the function else the program will never end

Advantage of Recurive Function

1.it makes the coding clean

2.it helps solve a complex problem by breaking it down into many parts

Question: Write a program to find the sum of a number from 1 to n using recursive function

Solution:

import java.util.Scanner;

public class Recursive1
    {
	static int sum=0;

	public static void main(String[] args)
	{
		Scanner s = new Scanner(System.in);
		System.out.print("Enter A number:");
		int n = s.nextInt();
		System.out.print("The sum of the numbers from 1 to " + n +" is " + sum(n));	
	}

	public static int sum(int n)
	{ 
		int i=n;
		if(i!= 0)
		{
			sum = sum + i;
			i--;
			return sum(i);
		}
		return(sum);				
	}
   }

Output:

Question: Write a program to find the factorial of a given number using recursive function

Solution:

import java.util.Scanner;
public class Recursive2
  {
	static int fac=1;

	public static void main(String[] args)
	{
		Scanner s = new Scanner(System.in);
		System.out.print("Enter A number:");
		int n = s.nextInt();
		System.out.print("The factorial of the number is " + n +" is " + fac(n));	
	}

	public static int fac(int n)
	{ 
		int i=n;
		if(i!= 0)
		{
			fac = fac * i;
			i--;
			return fac(i);
		}
		return(fac);				
	}
  }

output:

Question:Write a program to print multiplication table of any number from 1 to 12 using recursive function

Solution:

import java.util.Scanner;
public class Recursive3
  {
	static int i=1;
	public static void main(String[] args)
	{
		Scanner s = new Scanner(System.in);
		System.out.print("Enter A number:");
		int n = s.nextInt();
		System.out.print("The Multiplication table of " + n +" from 1 to 12 is \n");
		mut(n);	
	}

	public static int mut(int n)
	{ 
	
		if(i<=12)
		{
			System.out.println(i +"*"+ n+ " : " + (i*n));
			i++;
			fac(n);
		}
		return(n);				
	}
  }
  

output:

Question: Write a program to find the prime number using recursive program

Solution

import java.util.Scanner;
public class Recursive4
  {
	static int count=0;
	static int i=1;
	public static void main(String[] args)
	{
		Scanner s = new Scanner(System.in);
		System.out.print("Enter a number:");
		int n = s.nextInt();
		System.out.print("The given number "+ n +" ");
		check(n);
		if(count==2)
			System.out.print("is prime");
		else
			System.out.print("is not prime");
	
	}

	public static int check(int n)
	{ 
		if(i<=n)
		{
			if(n%i==0)
			{
				count++;
			}
			i++;
			return check(n);
		}	
		return count;
			
	}
}

Output:

Question: Write a program to find the cube of a given number

Solution:

import java.util.Scanner;

public class Recursive5
  {
	static int i =1;
	static int p =1;
	public static void main(String[] args)
	{
		Scanner s = new Scanner(System.in);
		System.out.print("Enter a number:");
		int n = s.nextInt();
		System.out.print("The cube of " + n+ " is " + cal(n));
	}

	public static int cal(int n)
	{ 
		if(i&jlt;=3)
		{
					p=p*n;
					i++;
					return cal(n);
		}						
			return p;
	}
}

output: