house robber ii solution

Implement dynamic programming solution for house robber problem.

Author: yhkee0404

house-robber-ii/yhkee0404.scala

@@ -0,0 +1,17 @@
+object Solution {
+    def rob(nums: Array[Int]): Int = {
+        if (nums.length == 1) {
+            return nums(0)
+        }
+        val dp = Array.fill(nums.length)(Array.fill(2)(0)) // T(n) = S(n) = O(n)
+        dp(0)(1) = nums(0)
+        dp(1)(0) = nums(1)
+        dp(1)(1) = nums(0)
+        for (i <- 2 until nums.length) {
+            for (j <- 0 to 1) {
+                dp(i)(j) = Math.max(dp(i - 1)(j), dp(i - 2)(j) + nums(i))
+            }
+        }
+        Math.max(dp(nums.length - 2)(1), dp(nums.length - 1)(0))
+    }
+}