DescriptionGiven a 2D board and a word, find if the word exists in the grid. The word can be constructed from letters of sequentially adjacent cell, where “adjacent” cells are those horizontally or ve

DescriptionTwo elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing its structure. The original problem is here. The original code is here.

DescriptionGiven a 2D board containing ‘X’ and ‘O’, capture all regions surrounded by ‘X’. A region is captured by flipping all ‘O’s into ‘X’s in that surrounded region. For example, X X X X X O O X X

DescriptionAll DNA is composed of a series of nucleotides abbreviated as A, C, G, and T, for example: “ACGAATTCCG”. When studying DNA, it is sometimes useful to identify repeated sequences within the

DescriptionGiven an unsorted array, find the maximum difference between the successive elements in its sorted form. Try to solve it in linear time/space. Return 0 if the array contains less than 2 ele

DescriptionGiven a 2D binary matrix filled with 0’s and 1’s, find the largest square containing all 1’s and return its area. For example, given the following matrix: 1 0 1 0 0 1 0 1 1 1 1 1 1 1 1 1 0

DescriptionSay you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete at most two transactions. Note:You m

DescriptionFollow up for “Search in Rotated Sorted Array”:What if duplicates are allowed? Would this affect the run-time complexity? How and why? Write a function to determine if a given target is in

DescriptionSuppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). You are given a target value to search. If found in the array re

DescriptionGiven a complete binary tree, count the number of nodes. The original problem is here. The original code is here.