Find two numbers that add up to a target using hash map.

Check if parentheses string is valid using stack approach.

Reverse a singly linked list using iterative approach.

Merge two strings by alternating their characters.

Check if an integer is a palindrome without converting to string.

Merge two sorted linked lists using dummy node approach.

Traverse binary tree inorder using recursive and iterative approaches.

Find maximum profit from stock prices using two pointers approach.

Check if two strings are anagrams using hash map approach.

Calculate the maximum depth of a binary tree using recursive approach.

Count distinct ways to climb stairs using 1 or 2 steps at a time. Fibonacci pattern.

Check if array contains any duplicate values using hash set approach.

Search sorted array by repeatedly dividing search space in half. O(log n) complexity.

Remove all occurrences of a value in-place using two pointers technique.

Find the length of the last word in a string using reverse traversal approach.

Increment a large integer represented as a digit array by one using in-place carry propagation.

Add two binary strings and return their sum using carry propagation from right to left.

Check if binary tree is symmetric using recursive mirror comparison approach.

Find maximum depth of N-ary tree using recursive DFS or iterative BFS.

Check if tree has root-to-leaf path where values sum to target.

Find the minimum depth using BFS or DFS approach.

Remove duplicates in-place using two pointers technique.

Move all zeroes to the end while maintaining non-zero order.

Detect cycle using Floyd's Tortoise and Hare algorithm.

Compute integer square root using binary search.

Check if binary tree is height-balanced using recursive depth calculation.

Build a height-balanced BST from sorted array using divide and conquer.

Invert a binary tree by swapping left and right nodes recursively. Create a mirror image.

Add two numbers represented as linked lists with carry handling.

Find the longest substring without repeating characters using sliding window technique.

Merge all overlapping intervals using sorting approach.