Coding Problems

Add two numbers represented as linked lists

Flatten a binary tree to a linked list in-place

Remove the nth node from the end of a linked list

Merge two sorted linked lists into one sorted list

Determine if a linked list has a cycle

Determine if a linked list is a palindrome

Implement wildcard pattern matching with ? (any char) and * (any sequence)

Place n queens on nxn chessboard so no two threaten each other

Find smallest missing positive integer in unsorted array

Determine if 9x9 Sudoku board is valid (no duplicates in rows/cols/boxes)

Rearrange numbers into lexicographically next greater permutation

Find all unique triplets that sum to 0

Find length of longest valid (well-formed) parentheses substring

Find longest common prefix string amongst array of strings

If element is 0, set entire row and column to 0 (in-place)

Rotate nxn matrix 90 degrees clockwise in-place

Return all elements in spiral order

Search sorted matrix (rows sorted, first of row > last of previous)

Design data structure supporting O(1) operations

Determine if you can reach last index (nums[i] = max jump)