Add solution #213

Author: JoshCrozier

README.md

@@ -89,6 +89,7 @@
 198|[House Robber](./0198-house-robber.js)|Medium|
 203|[Remove Linked List Elements](./0203-remove-linked-list-elements.js)|Easy|
 206|[Reverse Linked List](./0206-reverse-linked-list.js)|Easy|
+213|[House Robber II](./0213-house-robber-ii.js)|Medium|
 214|[Shortest Palindrome](./0214-shortest-palindrome.js)|Hard|
 217|[Contains Duplicate](./0217-contains-duplicate.js)|Easy|
 219|[Contains Duplicate II](./0219-contains-duplicate-ii.js)|Easy|

solutions/0213-house-robber-ii.js

@@ -0,0 +1,41 @@
+/**
+ * 213. House Robber II
+ * https://leetcode.com/problems/house-robber-ii/
+ * Difficulty: Medium
+ *
+ * You are a professional robber planning to rob houses along a street. Each house has a certain
+ * amount of money stashed. All houses at this place are arranged in a circle. That means the
+ * first house is the neighbor of the last one. Meanwhile, adjacent houses have a security system
+ * connected, and it will automatically contact the police if two adjacent houses were broken into
+ * on the same night.
+ *
+ * Given an integer array nums representing the amount of money of each house, return the maximum
+ * amount of money you can rob tonight without alerting the police.
+ */
+
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var rob = function(nums) {
+  if (nums.length === 1) {
+    return nums[0];
+  }
+
+  return Math.max(
+    handlePermutation(nums, 0, nums.length - 1),
+    handlePermutation(nums, 1, nums.length)
+  );
+};
+
+function handlePermutation(nums, start, end) {
+  let previous = 0, current = 0;
+
+  for (let i = start; i < end; i++) {
+    const temp = previous;
+    previous = current;
+    current = Math.max(temp + nums[i], previous);
+  }
+
+  return Math.max(current, previous);
+}