feat: add houseRobber implementation (TheAlgorithms#1282)

HereBeAndre · web-flow · commit c252df5d1035 · 2023-02-07T22:21:00.000+05:30
diff --git a/Dynamic-Programming/Sliding-Window/HouseRobber.js b/Dynamic-Programming/Sliding-Window/HouseRobber.js
@@ -0,0 +1,23 @@
+/**
+ * @function houseRobber
+ * @description 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}
+ * @see [Leetcode link](https://leetcode.com/problems/house-robber/)
+ */
+export const houseRobber = (nums) => {
+  const length = nums.length
+
+  if (length === 0) return 0
+  if (length === 1) return nums[0]
+  if (length === 2) return Math.max(nums[0], nums[1])
+
+  const dp = Array(length) // last element of this array always contains biggest loot possible
+  dp[0] = nums[0]
+  dp[1] = Math.max(nums[0], nums[1])
+
+  for (let i = 2; i < length; i++) {
+    dp[i] = Math.max(nums[i] + dp[i - 2], dp[i - 1])
+  }
+  return dp[length - 1]
+}
diff --git a/Dynamic-Programming/Sliding-Window/test/HouseRobber.test.js b/Dynamic-Programming/Sliding-Window/test/HouseRobber.test.js
@@ -0,0 +1,20 @@
+import { houseRobber } from '../HouseRobber'
+
+describe('houseRobber', () => {
+  it('expects to return 0 when argument is empty array', () => {
+    expect(houseRobber([])).toBe(0)
+  })
+
+  it('expects to return element at index 0 when argument is array of length one', () => {
+    expect(houseRobber([9])).toBe(9)
+  })
+
+  it('expects to return greater number when argument is an array of length two', () => {
+    expect(houseRobber([3, 6])).toBe(6)
+  })
+
+  it('expects to return the maximum loot possible', () => {
+    expect(houseRobber([1, 2, 3, 1])).toBe(4)
+    expect(houseRobber([2, 7, 9, 3, 1])).toBe(12)
+  })
+})
