05_GameOfLife.py

# Question link - https://leetcode.com/problems/game-of-life/description/?envType=study-plan-v2&envId=top-interview-150

class Solution:
    def gameOfLife(self, board: List[List[int]]) -> None:
        """
        Do not return anything, modify board in-place instead.
        1 - live cell , 0 - dead cell   
        following the structure of state
        original | new state | state
        --------- | ---------- | --------
        0         | 0          | 0
        1         | 0          | 1
        0         | 1          | 2
        1         | 1          | 3
        """


        ROWS , COLS = len(board) , len(board[0])

        # helper function
        def calcaluteNeighbours(r , c):
            nei = 0
            for i in range(r-1,r+2):
                for j in range(c-1,c+2):
                    if ((i==r and j==c) or i<0 or j<0 or i==ROWS or j==COLS):
                        continue
                    elif board[i][j] in [1,3]:
                        nei += 1
            return nei

        for r in range(ROWS):
            for c in range(COLS):
                # Calculate the neighbours
                nei = calcaluteNeighbours(r , c)
                if board[r][c]: #live
                    if nei in [2,3]:
                        board[r][c] = 3
                elif nei == 3:
                    board[r][c] = 2

        # Converting the board for 2 and 3 state
        for r in range(ROWS):
            for c in range(COLS):
                # State is 1 , then 0
                if board[r][c] == 1:
                    board[r][c] = 0
                elif board[r][c] in [2,3]:
                    board[r][c] = 1