矩阵中的路径

class Solution:
    # main
    def hasPath(self , matrix : str , rows : int  , cols : int , string : str ):
        #1.special cases
        if len(string)>len(matrix):
            return False
        if len(matrix)!= rows*cols:
            return False
        if rows<0&nbs***bsp;cols<0:
            return False
        
        # 2.construct matrix by string
        matrixList = []
        for i in range(rows):
            matrixList.append(list(matrix[i*cols:i*cols+cols]))
        #print(matrixList)
        
        #3.search the location of the String's first char,which is in the matrixlist
        firstCharAppearIndex = []
        for row in range(rows):
            for col in range(cols):
                if matrixList[row][col]==string[0]:
                    firstCharAppearIndex.append((row,col))
        if len(firstCharAppearIndex)==0:
            return False
        
        #4.Traversal search the sequence,use recursion method
        for idxTuple in firstCharAppearIndex:
            if self.findResultPath(matrixList,idxTuple,string):
                return True
            
        # worst result,cannot find a path then return False
        return False


    def findResultPath(self, matrixList:list , idxTuple:tuple , string:str):
        # idxtuple(row,col) index location of the first character of string,that is string[0]
        # 1.special cases
        if (not 0<=idxTuple[0]<len(matrixList))&nbs***bsp;(not  0<=idxTuple[1]<len(matrixList[0]))&nbs***bsp;\
            (matrixList[idxTuple[0]][idxTuple[1]]!=string[0]):
                return False
        if len(string)==1 and matrixList[idxTuple[0]][idxTuple[1]]==string[0]:
                return True
        # 2.search the surrounding element whether is equal to string[1]
        else:
            matrixList[idxTuple[0]][idxTuple[1]]=""
            res = self.findResultPath(matrixList=matrixList,idxTuple=(idxTuple[0],idxTuple[1]-1),string=string[1:]) \
               &nbs***bsp;self.findResultPath(matrixList=matrixList,idxTuple=(idxTuple[0],idxTuple[1]+1),string=string[1:]) \
               &nbs***bsp;self.findResultPath(matrixList=matrixList,idxTuple=(idxTuple[0]+1,idxTuple[1]),string=string[1:]) \
               &nbs***bsp;self.findResultPath(matrixList=matrixList,idxTuple=(idxTuple[0]-1,idxTuple[1]),string=string[1:]) 
            matrixList[idxTuple[0]][idxTuple[1]]=string[0]
            return res