Problem Statement: Given an m x n grid of characters board and a string word, return true if the word exists in the grid.

The word can be constructed from letters of sequentially adjacent cells, where adjacent cells are horizontally or vertically neighboring. The same letter cell may not be used more than once.

Solution: The basic approach to solving the word search problem using backtracking is to start at the first character of the word and check all 8 adjacent cells in the grid to see if any of them match the next character of the word. If a match is found, mark the cell as visited and recursively check the next character of the word in the adjacent cells of the newly visited cell. If the entire word is found, return true. If no match is found, backtrack to the previous cell and try a different path. Repeat this process until the entire grid has been searched or the word is found.

Wouldn't this be check all 4 adjacent cells?