289_Game_of_Life

Author: Partho Biswas

README.md

@@ -154,6 +154,7 @@ I have solved quite a number of problems from several topics. See the below tabl
 |46| **[359. Logger Rate Limiter](https://tinyurl.com/tcr34w3)** | [Python](https://tinyurl.com/wu6rdaw/359_Logger_Rate_Limiter.py)| --- | Easy | Hash and Set, Very important |
 |47| **[48. Rotate Image](https://tinyurl.com/yy3z9hab)** | [Python](https://tinyurl.com/wu6rdaw/48_Rotate_Image.py)| [Must](https://tinyurl.com/tr62top), [Vid  1](https://tinyurl.com/uhnruzt) | Medium | Very important |
 |48| **[362. Design Hit Counter](https://tinyurl.com/sswrcc3)** | [Python](https://tinyurl.com/wu6rdaw/362_Design_Hit_Counter.py), [Swift](https://tinyurl.com/wuja3c4/362_Design_Hit_Counter.swift)| --- | Medium | --- |
+|49| **[289. Game of Life](https://tinyurl.com/y5ujyvu5)** | [Python](https://tinyurl.com/wu6rdaw/289_Game_of_Life.py), [Swift](https://tinyurl.com/wuja3c4/289_Game_of_Life.swift)| --- | Medium | --- |
 
 
 </p>

leetcode.com/python/289_Game_of_Life.py

@@ -0,0 +1,56 @@
+# O(mn) approach
+class Solution(object):
+    def gameOfLife(self, board):
+        """
+        :type board: List[List[int]]
+        :rtype: None Do not return anything, modify board in-place instead.
+        """
+        neighbours = [(1, 0), (1, -1), (0, -1), (-1, -1), (-1, 0), (-1, 1), (0, 1), (1, 1)]
+        rows = len(board)
+        cols = len(board[0])
+        boardClone = [[board[row][col] for col in range(cols)] for row in range(rows)]
+        for row in range(rows):
+            for col in range(cols):
+                livingNeighbours = 0
+                for neighbour in neighbours:
+                    r = row + neighbour[0]
+                    c = col + neighbour[1]
+                    if (r < rows and r >= 0) and (c < cols and c >= 0) and (boardClone[r][c] == 1):
+                        livingNeighbours += 1
+                if boardClone[row][col] == 1 and (livingNeighbours < 2 or livingNeighbours > 3):
+                    board[row][col] = 0
+                if boardClone[row][col] == 0 and (livingNeighbours == 3):
+                    board[row][col] = 1
+
+
+# O(1) approach
+class Solution(object):
+    def gameOfLife(self, board):
+        """
+        :type board: List[List[int]]
+        :rtype: None Do not return anything, modify board in-place instead.
+        """
+        neighbours = [(1, 0), (1, -1), (0, -1), (-1, -1), (-1, 0), (-1, 1), (0, 1), (1, 1)]
+        rows = len(board)
+        cols = len(board[0])
+        for row in range(rows):
+            for col in range(cols):
+                livingNeighbours = 0
+                for neighbour in neighbours:
+                    r = row + neighbour[0]
+                    c = col + neighbour[1]
+                    if (r < rows and r >= 0) and (c < cols and c >= 0) and (abs(board[r][c]) == 1):
+                        livingNeighbours += 1
+                if board[row][col] == 1 and (livingNeighbours < 2 or livingNeighbours > 3):
+                    board[row][col] = -1
+                if board[row][col] == 0 and (livingNeighbours == 3):
+                    board[row][col] = 2
+        for row in range(rows):
+            for col in range(cols):
+                if board[row][col] > 0:
+                    board[row][col] = 1
+                else:
+                    board[row][col] = 0
+
+
+

leetcode.com/swift/DS_ALGO_PRAC.playground/Sources/swift/289_Game_of_Life.swift

@@ -0,0 +1,51 @@
+import Foundation
+
+class Solution {
+    func gameOfLife(_ board: inout [[Int]]) {
+        guard board.count > 0 else {
+            return
+        }
+        guard board[0].count > 0 else {
+            return
+        }
+        let rows = board.count
+        let cols = board[0].count
+        for row in 0..<rows {
+            for col in 0..<cols {
+                let livingNeighbours = self.getLivesCount(row, col, board)
+                if (board[row][col] == 1) && (livingNeighbours < 2 || livingNeighbours > 3) {
+                    board[row][col] = -1
+                }
+                if board[row][col] == 0 && livingNeighbours == 3 {
+                    board[row][col] = 2
+                }
+            }
+        }
+        for row in 0..<rows {
+            for col in 0..<cols {
+                if board[row][col] > 0 {
+                    board[row][col] = 1
+                } else {
+                    board[row][col] = 0
+                }
+            }
+        }
+    }
+    
+    private func getLivesCount(_ row: Int, _  col: Int, _ board: [[Int]]) -> Int {
+        let rows = board.count
+        let cols = board[0].count
+        var neighbours = [(1,0), (1,-1), (0,-1), (-1,-1), (-1,0), (-1,1), (0,1), (1,1)]
+        var livingNeighbours = 0
+        for neighbour in neighbours {
+            let r = row + neighbour.0
+            let c = col + neighbour.1
+            if (r < rows && r >= 0) && (c < cols && c >= 0) && (abs(board[r][c]) == 1) {
+                livingNeighbours += 1
+            }
+         }
+        return livingNeighbours
+    }
+}
+
+