【leetcode】1222. Queens That Can Attack the King

题目如下：

On an 8x8 chessboard, there can be multiple Black Queens and one White King.

Given an array of integer coordinates queens that represents the positions of the Black Queens, and a pair of coordinates king that represent the position of the White King, return the coordinates of all the queens (in any order) that can attack the King.

 

Example 1:

Input: queens = [[0,1],[1,0],[4,0],[0,4],[3,3],[2,4]], king = [0,0]
Output: [[0,1],[1,0],[3,3]]
Explanation:  
The queen at [0,1] can attack the king cause they're in the same row. 
The queen at [1,0] can attack the king cause they're in the same column. 
The queen at [3,3] can attack the king cause they're in the same diagnal. 
The queen at [0,4] can't attack the king cause it's blocked by the queen at [0,1]. 
The queen at [4,0] can't attack the king cause it's blocked by the queen at [1,0]. 
The queen at [2,4] can't attack the king cause it's not in the same row/column/diagnal as the king.

Example 2:

Input: queens = [[0,0],[1,1],[2,2],[3,4],[3,5],[4,4],[4,5]], king = [3,3]
Output: [[2,2],[3,4],[4,4]]

Example 3:

Input: queens = [[5,6],[7,7],[2,1],[0,7],[1,6],[5,1],[3,7],[0,3],[4,0],[1,2],[6,3],[5,0],[0,4],[2,2],[1,1],[6,4],
[5,4],[0,0],[2,6],[4,5],[5,2],[1,4],[7,5],[2,3],[0,5],[4,2],[1,0],[2,7],[0,1],[4,6],[6,1],[0,6],[4,3],[1,7]], king = [3,4]
Output: [[2,3],[1,4],[1,6],[3,7],[4,3],[5,4],[4,5]]

 

Constraints:

• 1 <= queens.length <= 63
• queens[0].length == 2
• 0 <= queens[i][j] < 8
• king.length == 2
• 0 <= king[0], king[1] < 8
• At most one piece is allowed in a cell.

解题思路：往king的上下左右，上左，上右，下左，下右八个方向移动，如果某个方向遇到queen，则表示这个queen能攻击到king，然后停止这个方向的移动。

代码如下：

class Solution(object):
    def queensAttacktheKing(self, queens, king):
        """
        :type queens: List[List[int]]
        :type king: List[int]
        :rtype: List[List[int]]
        """
        res = []
        dic = {}
        for (x,y) in queens:dic[(x,y)] = 1
        direction = [(0,1),(0,-1),(-1,0),(1,0),(-1,-1),(-1,1),(1,-1),(1,1)]
        for (x,y) in direction:
            kx,ky = king
            while kx + x >= 0 and kx + x < 8 and ky+y>=0 and ky+ y < 8:
                if (kx+x,ky+y) in dic:
                    res.append([kx+x,ky+y])
                    break
                kx += x
                ky += y
        return res