Given a 2D array A, each cell is 0 (representing sea) or 1 (representing...

There are N students in a class. Some of them are friends, while some ar...

An image is represented by a 2-D array of integers, each integer represe...

International Morse Code defines a standard encoding where each letter i...

Given a 2d grid map of '1's (land) and '0's (water), count the number of...

Given a non-empty 2D array grid of 0's and 1's, an island is a group of ...

There are N rooms and you start in room 0. Each room has a distinct num...

Given a binary tree, imagine yourself standing on the right side of it, ...