Program to Find nth Happy Number

Happy number: Replace the Number by the sum of the squares of its digits, and repeat the process. In the end, If the Number is equaled to 1 then it is a Happy Number.

Example:

               Given Number=10
               10⇒1²+0²=1
               10 is Happy Number.
                 
                Given Number=22
               22⇒2²+2²=8
               22 is an Unhappy Number.
                                          
Problem statement:-  Program to Find nth Happy Number.

Data requirement:-

   Input Data:- rangenumber

   Output Data:- rangenumber, letest

   Additional Data:- c, num, num1, sum, rem

Program in C

Here is the source code of the C Program to Find nth Happy Number.

Code:

//Nth Happy Number
#include <stdio.h>
int
main ()
{
  int i, rangenumber, num = 1, c = 0, letest = 0;
  printf ("Enter the Nth value:");
  scanf ("%d", &rangenumber);
  while (c != rangenumber)
    {
    int num1=num,sum=0,rem;
    while(sum!=1 && sum!=4)
     {
    sum=0;
    while(num1!=0)
    {
        rem=num1%10;
        sum+=(rem*rem);
        num1/=10;
    }
    num1=sum;
    }
   if(sum==1)
   {
          c++;
          letest=num;
    }
      num = num + 1;
    }
  printf ("%dth Happy number is %d", rangenumber, letest);
  return 0;
}

Input/Output:

Enter the Nth value:5
5th Happy number is 19

Program in C++

Here is the source code of the C++ Program to Find nth Happy Number.

Code:

#include <iostream>
using namespace std;
int
main ()
{
  int i, rangenumber, num = 1, c = 0, letest = 0;
  cout<<"Enter the Nth value:";
  cin>>rangenumber;

  int sum=0;
  while (c != rangenumber)
    {
    int num1=num,sum=0,rem;
    while(sum!=1 && sum!=4)
     {
    sum=0;
    while(num1!=0)
    {
        rem=num1%10;
        sum+=(rem*rem);
        num1/=10;
    }
    num1=sum;
    }
   if(sum==1)
   {
          c++;
          letest=num;
    }
      num = num + 1;
    }
  cout<<rangenumber<<"th Happy number is "<<letest;
  return 0;
}

Input/Output:

Enter the Nth value:7
7th Happy number is 28

Program in Java

  

Here is the source code of the Java Program to Find nth Happy Number.

Code:

import java.util.Scanner;
public class NthHappyNumber {
public static void main(String[] args) {
Scanner cs=new Scanner(System.in);
int  rangenumber, num = 1, c = 0, letest = 0;
  System.out.println("Enter Nth number:");
  rangenumber=cs.nextInt();
           
  while (c != rangenumber)
    {
  int num1=num,sum=0,rem;
    while(sum!=1 && sum!=4)
     {
    sum=0;
    while(num1!=0)
    {
        rem=num1%10;
        sum+=(rem*rem);
        num1/=10;
    }
    num1=sum;
    }
   if(sum==1)
      {
          c++;
          letest=num;
      }
      num = num + 1;
    }
System.out.println(rangenumber+"th Happy number is "+letest);
cs.close();
}}

Input/Output:

Enter Nth number:
17
17th Happy number is 91

Program in Python
  

Here is the source code of the Program to Find nth Happy Number.

Code:

rangenumber=int(input("Enter a Nth Number:"))
c = 0
letest = 0
num = 1
while c != rangenumber:
    sum = 0
    num1=num
    while sum != 1 and sum != 4:
        sum = 0
        while num1 != 0:
            rem = num1 % 10
            sum += (rem * rem)
            num1 //= 10
        num1 = sum

    if sum == 1:
            c+=1
            letest = num

    num = num + 1
print(rangenumber,"th Happy number is ",letest)

Input/Output:

Enter a Nth Number:25
25 th Happy number is  133

More:-

C/C++/Java/Python Practice Question