剑指Offer60-矩阵中的路径（记忆）

# -*- coding:utf-8 -*-
class Solution:
    def hasPath(self, matrix, rows, cols, path):
        # write code here
        matrix_two = [[0 for i in range(cols)] for j in range(rows)]
        visited = [[False for i in range(cols)] for j in range(rows)]
        # matrix_two是由matrix转成二维矩阵的
        # visited是用来做记录的，每次如果走过的位置，就会变成True
        
        for i in range(rows):
            for j in range(cols):
                matrix_two[i][j] = matrix[i*cols + j]  # matrix转二维
        
        def dfs(kth, i, j):
            # kth是指在path上的index
            if kth == len(path):
                return True
            res = False
            if 0<=i<rows and 0<=j<cols and matrix_two[i][j]==path[kth] and visited[i][j] is not True:
                visited[i][j] = True
                res = dfs(kth+1, i+1,j) or dfs(kth+1, i-1,j) or dfs(kth+1, i,j+1) or dfs(kth+1, i,j-1)
                if res is not True:
                    visited[i][j] = False
            return res
        
        for i in range(rows):
            for j in range(cols):
                if dfs(0, i, j):
                    return True
        return False