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Game of Life

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Description

https://leetcode.com/problems/game-of-life/description/

Solution

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class Solution:
    def gameOfLife(self, board):
        """
        :type board: List[List[int]]
        :rtype: void Do not return anything, modify board in-place instead.
        """
        if board is None or len(board) == 0:
            return
        
        directions = [(-1, -1), (-1, 0), (-1, 1), (0, -1), (0, 1), (1, -1), (1, 0), (1, 1)]
        for i in range(len(board)):
            for j in range(len(board[0])):
                self.transform(i, j, board, directions)
        
        for i in range(len(board)):
            for j in range(len(board[0])):
                board[i][j] >>= 1
        
    def transform(self, x, y, board, directions):
        
        count = 0
        for direction in directions:
            if direction[0] + x >= 0 and direction[0] + x < len(board) and \
                direction[1] + y >= 0 and direction[1] + y < len(board[0]) and \
                    board[direction[0] + x][direction[1] + y] & 1 == 1:
                count += 1
        
        if (board[x][y] & 1) == 1:
            if count == 2 or count == 3:
                board[x][y] = board[x][y] + 2
        else:
            if count == 3:
                board[x][y] = board[x][y] + 2