adding algo

src/my_project/interviews/top_150_questions_round_22/ex_37_game_of_life.py

@@ -0,0 +1,44 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+
+class Solution:
+    def gameOfLife(self, board: List[List[int]]) -> None:
+
+        """
+        Do not return anything, modify board in-place instead.
+        """
+        ## RC ##
+        ## APPRAOCH : IN-PLACE MANIPULATION ##
+        #  when the value needs to be updated, we donot just change  
+        # 0 to 1 / 1 to 0 but we do in increments and decrements of 2. 
+        # (table explains)        
+        ##   previous value state change  current state   current value
+        ##   0              no change     dead            0
+        ##   1              no change     live            1
+        ##   0              changed (+2)  live            2
+        ##   1              changed (-2)  dead            -1
+
+		## TIME COMPLEXITY : O(MxN) ##
+		## SPACE COMPLEXITY : O(1) ##       
+
+        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])):
+                live = 0
+                for x, y in directions:
+                    if ( 0<= i + x < len(board)) \
+                        and (0<= j + y < len(board[0])) \
+                        and abs(board[i+x][j+y]) == 1:
+                        live += 1
+
+                if board[i][j] == 1 and (live < 2 or live > 3):
+                    board[i][j] = -1
+                if board[i][j] == 0 and live == 3:
+                    board[i][j] = 2
+
+        for i in range(len(board)):
+            for j in range(len(board[0])):
+                board[i][j] = 1 if(board[i][j] > 0) else 0
+        return board                    
+

tests/test_150_questions_round_22/test_37_game_of_life_round_22.py

@@ -0,0 +1,17 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_22\
+.ex_37_game_of_life import Solution
+
+class GameOfLifeTestCase(unittest.TestCase):
+
+    def test_first_pattern(self):
+        solution = Solution()
+        output = solution.gameOfLife(board = [[0,1,0],[0,0,1],[1,1,1],[0,0,0]])
+        target = [[0,0,0],[1,0,1],[0,1,1],[0,1,0]]
+        self.assertEqual(output, target)
+
+    def test_second_pattern(self):
+        solution = Solution()
+        output = solution.gameOfLife(board = [[1,1],[1,0]])
+        target = [[1,1],[1,1]]
+        self.assertEqual(output, target)