[IMP] Array-2

find-all-numbers-disappeared-in-an-array.py

@@ -0,0 +1,38 @@
+class Solution:
+    '''
+    TC: O(2n) = O(n)
+    SC: O(1)
+    Leetcode: Compeleted the problem
+    Issue: no issue
+    '''
+    def findDisappearedNumbers(self, nums):
+        n = len(nums)
+        for i in range(n):
+            # Convert to abs to get the actual element
+            idx = abs(nums[i]) - 1
+
+            if nums[idx] > 0:
+                # convert the element to neg to mark it as available.
+                nums[idx] = - nums[idx]
+
+        res = []
+        # Get the result
+        for i in range(n):
+            if nums[i] > 0:
+                # + 1 for getting index for 0 based list.
+                res.append(i + 1)
+
+        return res
+
+    def findDisappearedNumbers(self, nums):
+        n = len(nums)
+        id = nums[0]
+
+
+
+
+s = Solution()
+nums = [4,3,2,7,8,2,3,1]
+print(s.findDisappearedNumbers(nums))
+nums = [1,1]
+print(s.findDisappearedNumbers(nums))

game-of-life.py

@@ -0,0 +1,50 @@
+class Solution:
+    '''
+    TC: O(n^2)
+    SC: O(1)
+    Leetcode: Completed with no issue
+    issueAny problem you faced while coding this : no issue.
+    '''
+    def countAlive(self, board, i, j, n, m):
+        count = 0
+        dirs = [(-1,-1),(-1,0),(-1,1),(0,-1),(0,1),(1,-1),(1,0),(1,1)]
+        for x, y in dirs:
+            rx = x + i
+            ry = y + j
+            if 0 <= rx < n and 0 <= ry < m:
+                if board[rx][ry] in [1, 2]:
+                    count += 1
+
+        return count
+
+    def gameOfLife(self, board):
+        """
+        Do not return anything, modify board in-place instead.
+        """
+        n = len(board)
+        m = len(board[0])
+
+        for i in range(n):
+            for j in range(m):
+                countAlive = self.countAlive(board, i, j, n, m)
+                if board[i][j] == 1:
+                    if countAlive < 2 or countAlive > 3:
+                        board[i][j] = 2
+                else:
+                    if countAlive == 3:
+                        board[i][j] = 3
+
+        for i in range(n):
+            for j in range(m):
+                if board[i][j] == 2:
+                    board[i][j] = 0
+                if board[i][j] == 3:
+                    board[i][j] = 1
+
+s = Solution()
+board = [[0,1,0],[0,0,1],[1,1,1],[0,0,0]]
+s.gameOfLife(board)
+print(board)
+board = [[1,1],[1,0]]
+s.gameOfLife(board)
+print(board)