array-2 completed

find-disapprearing-numbers.py

@@ -0,0 +1,33 @@
+# Loop through nums. If the element is >0 go to the elelment-1 th index and make the 
+# element there negative if it is postive . Else if the element<0, go to the index of the 
+# abs(element) and make the element negative if its positive.
+
+# Loop through the nums array array and check if any element is > 0, if so append it to an 
+# array and return the array
+
+# Time complexity: O(n)
+# Space complexity: O(1)
+
+class Solution(object):
+    def findDisappearedNumbers(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: List[int]
+        """
+
+        for i in nums:
+            if i>0:
+                nums[i-1]= -1*nums[i-1] if nums[i-1]>0 else nums[i-1]
+            elif i<0:
+                r=(-1*i)-1
+                nums[r]=-1*nums[r] if nums[r]>0 else nums[r]
+        arr=[]
+        for ind, i in enumerate(nums):
+            if i >0:
+                arr.append(ind+1)
+        return arr
+
+
+
+
+

game-of-life.py

@@ -0,0 +1,63 @@
+# Loop through each element in the array and check if it is alive:
+# Iterate through all its 8 neigbours to count the number of dead and live neighbpurs:
+# If the element ==1 and live<2, change the cell to 2
+# If the element ==1 and live> 3, change the cell to 2
+# If the element ==0 and live==3, change the cell to 3
+
+# In the end, loop through all the elements and change the cells with 2 to 0 and 3 to 1 
+# and return the matrix
+# Time complexity:O(n)
+# Space complexity:(1)
+
+
+class Solution(object):
+    def isAlive(self,r, c, board):
+        current_state=board[r][c]
+        dir = [[-1,0],[1,0],[0,1],[0,-1],[-1,1],[1,1],[1,-1],[-1,-1]]
+        live=0
+        dead=0
+        for i in dir:
+            nr = r+i[0]
+            nc= c+i[1]
+            if 0<=nr<len(board) and 0<=nc<len(board[0]):
+                if board[nr][nc] in [1,2]:
+                    live+=1
+                else:
+                    dead+=1
+        print("live", live,"dead",dead)
+        if current_state==1 and live<2:
+            return 2
+        elif current_state==1 and live in [2,3]:
+            return 1
+        elif current_state==1 and live>3:
+            return 2
+        elif current_state==0 and live==3:
+            return 3
+        return current_state
+
+
+
+
+    def gameOfLife(self, board):
+        """
+        :type board: List[List[int]]
+        :rtype: None Do not return anything, modify board in-place instead.
+        """
+        r=len(board)
+        c=len(board[0])
+
+        for i in range(r):
+            for j in range(c):
+                x=self.isAlive(i,j,board)
+                board[i][j]= x
+        print(board)
+        for i in range(r):
+            for j in range(c):
+                if board[i][j]==2:
+                    board[i][j]=0
+                elif board[i][j] == 3:
+                    board[i][j] =1
+
+
+
+