------------------------------------------ 🔹 Approach 1: Modulo Operator (%) - If a number divided by 2 has no remainder, it is even. - Classic and

------------------------------------------ 🔹 Approach 2: Bitwise AND Operator (&) - Binary trick: even numbers have 0 as the last bit. - Checking (n &

------------------------------------------ 🔹 Approach 3: Integer Division Trick - Divide the number by 2 and multiply it back. - If the result equals

------------------------------------------ 🔹 Approach 4: Recursive Method - Subtract 2 recursively until 0 or 1. - Base Case: 0 = even, 1 = odd. - Gre

Main function - using the most optimal approach

Approach 2: Memoization (Top-Down DP) Time: O(n), Space: O(n) - memoization table + recursion stack

Approach 4: Space Optimization Time: O(n), Space: O(1) - only two variables

Approach 1: Recursion (Brute Force) Time: O(2^n), Space: O(n) - recursion stack

Approach 3: Tabulation (Bottom-Up DP) Time: O(n), Space: O(n) - DP array

Helper to find the maximum element in the array

Helper function to find the middle of the list

Inorder traversal to find kth smallest element

------------------------------------------ 🔹 Approach 1: Iterative with Full If-Else - Extracts each digit - Cubes it and adds to sum - Compares sum t

Helper function to check if a substring is palindrome

Helper function to check if a substring is a palindrome

🔸 Approach 1: Two-Pointer Technique

🔸 Approach 2: Reverse and Compare

🔸 Approach 4: Compare First Half with Second Half

🔸 Approach 1: Reverse Integer and Compare

🔸 Approach 2: String-Based Two Pointers

--------------------------------------------------- 🔸 Approach 1: Brute Force - Check all numbers from 2 to n-1 - If any divides n evenly, it is not p

--------------------------------------------------- 🔸 Approach 2: Optimized Check (Up to √n) - If n has a factor larger than √n, then it must have o

Helper function with divisor `i`

Check if it's safe to place a queen at (row, col)

Helper function to check if two trees are identical

Helper function to check if placing queen at (row, col) is valid

Helper function to check if tree is valid BST within given range

🔹 Driver Code

🔹 Driver Code

🔹 Driver Code

Returns the maximum path sum that can be extended from current node