SDE - 1

You are given a 2D board('N' rows and 'M' columns) of characters and a string 'word'.

Your task is to return true if the given word exists in the grid, else return false. The word can be constructed from letters of sequentially adjacent cells, where adjacent cells are horizontally or vertically neighboring.

Note:

The same letter cell should not be used more than once.

For Example:

For a given word “design” and the given 2D board 
[[q’, ‘v’, ‘m’, ‘h’],
 [‘d’, ‘e’, ‘s’, ‘i’],
 [‘d’, ‘g’, ‘f’, ‘g’],
 [‘e’, ‘c’, ‘p’, ‘n’]]

The word design can be formed by sequentially adjacent cells as shown by the highlighted color in the 2nd row and last column.

You are given a two-dimensional grid having 'N' rows and 'M' columns, consisting of upper case characters. You are also given a word 'WORD'. You have to find the number of occurrences of that word in the grid.

Starting from a given cell, a word can be formed by moving in all eight directions: horizontally left, horizontally right, vertically up, vertically down, and four diagonal directions.

Example :

There are three occurrences of the word 'NINJA' in the following grid:

Note :

1) Given word will not be a single character.

2) If occurrences of the given word start from two different cells, then these two occurrences are considered to be different.

Consider the word 'XYX' to be searched in the string 'AXYXB'. Here, we find an occurrence of 'XYX' at index 2 going in the right direction, and another occurrence at index 4 going in the left direction.

Although these two words correspond to the same word, they will be considered as different occurrences.

Asked to design a photo-sharing app like Instagram.

Diamond Problem

Inheritance in JAVA

Singleton Design Pattern