Happy Number LeetCode Programming Solutions | LeetCode Problem Solutions in C++, Java, & Python [💯Correct]

LeetCode Problem | LeetCode Problems For Beginners | LeetCode Problems & Solutions | Improve Problem Solving Skills | LeetCode Problems Java | LeetCode Solutions in C++

Hello Programmers/Coders, Today we are going to share solutions to the Programming problems of LeetCode Solutions in C++, Java, & Python. At Each Problem with Successful submission with all Test Cases Passed, you will get a score or marks and LeetCode Coins. And after solving maximum problems, you will be getting stars. This will highlight your profile to the recruiters.

In this post, you will find the solution for the Happy Number in C++, Java & Python-LeetCode problems. We are providing the correct and tested solutions to coding problems present on LeetCode. If you are not able to solve any problem, then you can take help from our Blog/website.

Use “Ctrl+F” To Find Any Questions Answer. & For Mobile User, You Just Need To Click On Three dots In Your Browser & You Will Get A “Find” Option There. Use These Option to Get Any Random Questions Answer.

About LeetCode

LeetCode is one of the most well-known online judge platforms to help you enhance your skills, expand your knowledge and prepare for technical interviews. 

LeetCode is for software engineers who are looking to practice technical questions and advance their skills. Mastering the questions in each level on LeetCode is a good way to prepare for technical interviews and keep your skills sharp. They also have a repository of solutions with the reasoning behind each step.

LeetCode has over 1,900 questions for you to practice, covering many different programming concepts. Every coding problem has a classification of either Easy, Medium, or Hard.

LeetCode problems focus on algorithms and data structures. Here is some topic you can find problems on LeetCode:

• Mathematics/Basic Logical Based Questions
• Arrays
• Strings
• Hash Table
• Dynamic Programming
• Stack & Queue
• Trees & Graphs
• Greedy Algorithms
• Breadth-First Search
• Depth-First Search
• Sorting & Searching
• BST (Binary Search Tree)
• Database
• Linked List
• Recursion, etc.

Leetcode has a huge number of test cases and questions from interviews too like Google, Amazon, Microsoft, Facebook, Adobe, Oracle, Linkedin, Goldman Sachs, etc. LeetCode helps you in getting a job in Top MNCs. To crack FAANG Companies, LeetCode problems can help you in building your logic.

Link for the Problem – Happy Number– LeetCode Problem

Happy Number– LeetCode Problem

Problem:

Write an algorithm to determine if a number n is happy.

A happy number is a number defined by the following process:

• Starting with any positive integer, replace the number by the sum of the squares of its digits.
• Repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1.
• Those numbers for which this process ends in 1 are happy.

Return true if n is a happy number, and false if not.

Example 1:

Input: n = 19
Output: true
Explanation:
12 + 92 = 82
82 + 22 = 68
62 + 82 = 100
12 + 02 + 02 = 1

Example 2:

Input: n = 2
Output: false

Constraints:

• 1 <= n <= 231 - 1

Happy Number– LeetCode Solutions

Happy Number Solution in C++:

class Solution {
 public:
  bool isHappy(int n) {
    int slow = squaredSum(n);
    int fast = squaredSum(squaredSum(n));

    while (slow != fast) {
      slow = squaredSum(slow);
      fast = squaredSum(squaredSum(fast));
    }

    return slow == 1;
  }

 private:
  int squaredSum(int n) {
    int sum = 0;
    while (n) {
      sum += pow(n % 10, 2);
      n /= 10;
    }
    return sum;
  };
};

Happy Number Solution in Java:

class Solution {
  public boolean isHappy(int n) {
    int slow = squaredSum(n);
    int fast = squaredSum(squaredSum(n));

    while (slow != fast) {
      slow = squaredSum(slow);
      fast = squaredSum(squaredSum(fast));
    }

    return slow == 1;
  }

  private int squaredSum(int n) {
    int sum = 0;
    while (n > 0) {
      sum += Math.pow(n % 10, 2);
      n /= 10;
    }
    return sum;
  }
}

Happy Number Solution in Python:

class Solution:
  def isHappy(self, n: int) -> bool:
    def squaredSum(n: int) -> bool:
      sum = 0

      while n:
        sum += pow(n % 10, 2)
        n //= 10

      return sum

    slow = squaredSum(n)
    fast = squaredSum(squaredSum(n))

    while slow != fast:
      slow = squaredSum(slow)
      fast = squaredSum(squaredSum(fast))

    return slow == 1

• Time: O(log n)
• Space: O(1)