def existboard ListListstr word str 完成了搜索功能 param board 二维的字母表 param word 待搜索的单词 return 返回是否搜索到如果有则返回 true否则返回 false

from typing import List

def exist(board: List[List[str]], word: str) -> bool: """ 完成了搜索功能 :param board: 二维的字母表 :param word: 待搜索的单词 :return: 返回是否搜索到，如果有，则返回 true，否则返回 false """ def dfs(i, j, k): if not 0 <= i < len(board) or not 0 <= j < len(board[0]) or board[i][j] != word[k]: return False if k == len(word) - 1: return True tmp, board[i][j] = board[i][j], '/' res = dfs(i + 1, j, k + 1) or dfs(i - 1, j, k + 1) or dfs(i, j + 1, k + 1) or dfs(i, j - 1, k + 1) board[i][j] = tmp return res

for i in range(len(board)):
    for j in range(len(board[0])):
        if dfs(i, j, 0):
            return True
return Fals