add solution: house-robber-ii

Author: dusunax

house-robber-ii/dusunax.py

@@ -0,0 +1,48 @@
+'''
+# 213. House Robber II
+
+house roober 1 + circular array
+
+## Solution
+solve by using two cases:
+- robbing from the first house to the last house
+- robbing from the second house to the last house
+'''
+class Solution:
+    '''
+    A. pass indices to function
+    TC: O(n)
+    SC: O(1)
+    '''
+    def rob(self, nums: Lit[int]) -> int:
+        if len(nums) == 1:
+            return nums[0]
+
+        def robbing(start, end):
+            prev, maxAmount = 0, 0
+
+            for i in range(start, end):
+                prev, maxAmount = maxAmount, max(maxAmount, prev + nums[i])
+            
+            return maxAmount
+
+        return max(robbing(0, len(nums) - 1), robbing(1, len(nums)))
+
+    '''
+    B. pass list to function
+    TC: O(n)
+    SC: O(n) (list slicing)
+    '''
+    def robWithSlicing(self, nums: List[int]) -> int:
+        if len(nums) == 1:
+            return nums[0]
+
+        def robbing(nums):
+            prev, maxAmount = 0, 0
+
+            for num in nums:
+                prev, maxAmount = maxAmount, max(maxAmount, prev + num)
+            
+            return maxAmount
+
+        return max(robbing(nums[1:]), robbing(nums[:-1]))