Word Search
Solution:
- Scan matrix and pass board, coords and word to dfs recursive search for 'word' by letter
- Pretty much identical to "Number of Islands" only difference is implementation of temp variable to hold the preserved board
- As letters are found they are updated to '#' to prevent double counting a letter but if the recurvise search finds some but not all letters in a word we still need to be able to restore the board to continue the scan of the matrix once the 'dfs' function completely finishes
Output: True
class Solution:
def exist(self, board, word):
if not board:
return False
for i in range(len(board)):
for j in range(len(board(i))):
if self.dfs(board, i, j, word):
return True
def dfs(self, board, i, j, word):
if len(word) == 0
return True
if i < 0 or j < 0 or i >= len(board) or j >= len(board[i]) or word[0] != board[i][j]
return False
temp = board[i][j]
boardp[i][j] = "#"
result = self.dfs(board, i+1, j, word[1:]) or self.dfs(board, i-1, j, word[1:]) or self.dfs(board, i, j+1, word[1:]) or self.dfs(board, i, j-1, word[1:])
board[i][j] = temp
return result
board = [
["A","B","C","E"],["S","F","C","S"],["A","D","E","E"]
]
word = "ABCCED"
p1 = Solution()
print(p1.exist(board, word))