Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtr...

Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtr...

Given s1, s2, s3, find whether s3 is formed by the interleaving of s1 and s2. Example 1: 12Input: s1 = "aabcc", s2 ...

Reverse a linked list from position m to n. Do it in one-pass. Note: 1 ≤ m ≤ n ≤ length of list. Example: 12Input: 1->2-&g...

Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary). You may assume that ...

Given an unsorted integer array, find the smallest missing positive integer. Example 1: 12Input: [1,2,0]Output: 3 Example 2:...

Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order. For example,Given th...

Write a program to find the nth super ugly number. Super ugly numbers are positive numbers whose all prime factors are in the...

Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand. (i.e., [0,0,1,2,2,5,6] might b...

Given a linked list and a value x, partition it such that all nodes less than x come before nodes greater than or equal to x....