solve house roubber il

house-robber-ii/samthekorean.py

@@ -0,0 +1,30 @@
+# TC : O(n), where n is the number of houses.
+# SC : O(1)
+class Solution:
+    def rob(self, nums):
+        n = len(nums)
+        if n == 1:
+            return nums[0]
+        if n == 2:
+            return max(nums[0], nums[1])
+        if n == 3:
+            return max(nums[0], max(nums[1], nums[2]))
+
+        a = nums[0]
+        b = max(nums[0], nums[1])
+        c = -1
+        a1 = nums[1]
+        b1 = max(nums[1], nums[2])
+        c1 = -1
+
+        for i in range(2, n):
+            if i < n - 1:
+                c = max(nums[i] + a, b)
+                a = b
+                b = c
+            if i > 2:
+                c1 = max(nums[i] + a1, b1)
+                a1 = b1
+                b1 = c1
+
+        return max(c, c1)