我正在尝试解决Hackerrank上的Botclean问题：https://www.hackerrank.com/challenges/botclean

我想到的解决方案是扫描棋盘，找到距离最近的脏污方块，然后导航到该方块，清洁它，并重复此过程直到所有方块都清洁。

代码：

nextD = []def next_move(posr, posc, board):    global nextD    if nextD == []:        nextD = next_d(posr,posc,board)    if (nextD[0] == posr) and (nextD[1] == posc):        print("CLEAN")        board[posr][posc] = "-"        nextD = []        return     if posc < nextD[1]:        print("RIGHT")        return        #posc += 1    elif posc > nextD[1]:        print("LEFT")        return        #posc -= 1     if posr < nextD[0]:        print("DOWN")        return        #posr += 1    elif posr > nextD[0]:        print("UP")        return        #posr -= 1#find closest ddef next_d(posr, posc, board):    arr = []    for i in range(len(board)):        try:            #print("Distance to: ", i, board[i].index('d'), abs(i-posc) + abs(board[i].index('d')))            vals = [abs(i-posr) + abs(board[i].index('d')-posc), i, board[i].index('d')]            arr.append(vals)        except ValueError:            pass    arr.sort()    return [arr[0][1], arr[0][2]]# Tail starts hereif __name__ == "__main__":    pos = [int(i) for i in input().strip().split()]    board = [[j for j in input().strip()] for i in range(5)]    next_move(pos[0], pos[1], board)

我卡在了17.60/17.82的分数上。我的机器人在测试用例中获得了16、20、34、26的分数。最佳分数是16、25、28和18。讨论中提到应该实现贪婪算法，但我不是很确定在这种情况下该如何实现。有什么优化这个问题的建议吗？我是不是完全走错了方向？

编辑：时间不是评判标准。所以反复扫描棋盘不一定是问题。

如果你想观看它的实际操作：https://www.hackerrank.com/showgame/4843664

谢谢！

回答：

明白了

nextD = []def next_move(posr, posc, board):    global nextD    if nextD == []:        nextD = next_d(posr,posc,board)    if (nextD[0] == posr) and (nextD[1] == posc):        print("CLEAN")        board[posr][posc] = "-"        nextD = []    elif posc < nextD[1]:        print("RIGHT")    elif posc > nextD[1]:        print("LEFT")    elif posr < nextD[0]:        print("DOWN")    elif posr > nextD[0]:        print("UP")#find closest ddef next_d(posr, posc, board):    val = len(board) * 2    nextD = []    for i in range(len(board)):        for j in range(len(board[i])):            if board[i][j] == 'd' and abs(i - posr) + abs(j - posc) < val:                val = abs(i - posr) + abs(j - posc)                nextD = [i, j]    return nextD# Tail starts hereif __name__ == "__main__":    pos = [int(i) for i in input().strip().split()]    board = [[j for j in input().strip()] for i in range(5)]    next_move(pos[0], pos[1], board)