Example 1:
Input: board = [
["a","b","c","d"],
["s","a","a","t"],
["a","c","k","e"],
["a","c","d","n"]
],
words = ["bat","cat","back","backend","stack"]
Output: ["cat","back","backend"]
Example 2:
Input: board = [
["x","o"],
["x","o"]
],
words = ["xoxo"]
Output: []
Given a 2-D grid of characters board and a list of strings words, return all words that are present in the grid.
For a word to be present it must be possible to form the word with a path in the board with horizontally or vertically neighboring cells. The same cell may not be used more than once in a word.
1 <= board.length, board[i].length <= 12board[i] consists only of lowercase English letters.1 <= words.length <= 30,0001 <= words[i].length <= 10words[i] consists only of lowercase English letters.words are distinct.Reported as LeetCode 212 in a software engineer phone screen.