Clone a graph. Input is a Node pointer. Return the Node pointer of the cloned graph.

Determine whether an integer is a palindrome. Do this without extra space.

Given a string S, find the longest palindromic substring in S.

Note:
This is Part II of the article: Longest Palindromic Substring. Here, we describe an algorithm (Manacher’s algorithm) which finds the longest palindromic substring in linear time. Please read Part I for more background information.

Given a string S, find the longest palindromic substring in S.

Implement regular expression matching with support for ‘.’ and ‘*’.

Given a node from a cyclic linked list which has been sorted, write a function to insert a value into the list such that it remains a cyclic sorted list. The given node can be any single node in the list.

Reverse bits of an unsigned integer.

Given a binary tree, find the lowest common ancestor of two given nodes in the tree. Each node contains a parent pointer which links to its parent.

Given a binary tree, find the lowest common ancestor of two given nodes in the tree.

Given a binary search tree (BST), find the lowest common ancestor of two given nodes in the BST.