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Check if Number is Palindrome

Certification: Basic Level Accuracy: 83.33% Submissions: 6 Points: 5

Write a Java program to determine whether an integer is a palindrome. Do not convert the integer to a string — solve it mathematically.

Example 1
    

  • Input: x = 121
    • 

  • Output: true
    • 

  • Explanation:

      

    • Reverses to same value → it is a palindrome
      • 

    

    •
Example 2
    

  • Input: x = -121
    • 

  • Output: false
    • 

  • Explanation:

      

    • Negative values are not palindromes
      • 

    

    •
Constraints
    

  • -2^31 ≤ x ≤ 2^31 - 1
    • 

  • Do not convert to string
    • 

  • Time Complexity: O(log n)
    • 

  • Space Complexity: O(1)
    •
NumberSnowflakeTutorix
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Hint
Solution

Solution Hints

    
  
  • Negative numbers are not palindromes due to the minus sign.
    • 
  
  • Reverse the integer by extracting digits from right to left.
    • 
  
  • Be careful about integer overflow when reversing.
    • 
  
  • Compare the reversed integer with the original.
    • 
  
  • Handle edge cases like numbers ending with 0.
    •

Steps to solve by this approach:

 Step 1: Handle edge cases - check if the number is negative (not a palindrome).

 Step 2: Check if the number ends with 0 and is not 0 itself (not a palindrome).

 Step 3: Initialize a variable to store the reversed number.

 Step 4: Extract digits from the original number one by one from right to left.

 Step 5: Build the reversed number by adding each digit and multiplying the previous sum by 10.

 Step 6: After reversing the entire number, compare it with the original number.

 Step 7: Return true if they are equal, false otherwise.

Submitted Code :