✨ House Robber 3

README.md

@@ -221,7 +221,8 @@ npm run test // also you can run `npm run watch`
 | 192 |                            [MaxAreaOfIsLand](src/maxAreaOfIsLand/index.ts)                            |              [:green_book:](src/maxAreaOfIsLand/README.md)               |    Easy    | [LeetCode](https://leetcode.com/problems/max-area-of-island)                                | DFS         |
 | 193 |                                  [FloodFill](src/floodFill/index.ts)                                  |                 [:green_book:](src/floodFill/README.md)                  |    Easy    | [LeetCode](https://leetcode.com/problems/flood-fill)                                        | DFS         |
 | 194 |                      [BalancedBinaryTree](src/trees/balancedBinaryTree/index.ts)                      |          [:green_book:](src/trees/balancedBinaryTree/README.md)          |    Easy    | [LeetCode](https://leetcode.com/problems/balanced-binary-tree)                              | DFS         |
-| 195 |                              [FriendCircles](src/friendCircles/index.ts)                              |               [:green_book:](src/friendCircles/README.md)                |    Easy    | [LeetCode](https://leetcode.com/problems/friend-circles)                                    | DFS         |
+| 195 |                              [FriendCircles](src/friendCircles/index.ts)                              |               [:green_book:](src/friendCircles/README.md)                |   Medium   | [LeetCode](https://leetcode.com/problems/friend-circles)                                    | DFS         |
+| 196 |                               [HouseRobber3](src/houseRobber3/index.ts)                               |                [:green_book:](src/houseRobber3/README.md)                |   Medium   | [LeetCode](https://leetcode.com/problems/house-robber-iii)                                  | DFS         |
 
 ## Collaborators
 

src/trees/houseRobber3/README.md

@@ -0,0 +1,35 @@
+# 196.House Robber III
+
+## Description
+
+The thief has found himself a new place for his thievery again. There is only one entrance to this area, called the "root." Besides the root, each house has one and only one parent house. After a tour, the smart thief realized that "all houses in this place forms a binary tree". It will automatically contact the police if two directly-linked houses were broken into on the same night.
+
+Determine the maximum amount of money the thief can rob tonight without alerting the police.
+
+## Example1
+
+```javascript
+    3
+    / \
+   2   3
+    \   \
+     3   1
+
+Maximum amount of money the thief can rob = 3 + 3 + 1 = 7.
+```
+
+## Example2
+
+```javascript
+     3
+    / \
+   4   5
+  / \   \
+ 1   3   1
+
+Maximum amount of money the thief can rob = 4 + 5 = 9.
+```
+
+## From
+
+[LeetCode](https://leetcode.com/problems/house-robber-iii)

src/trees/houseRobber3/index.ts

@@ -0,0 +1,15 @@
+// HELP:
+
+import { I_TreeNode } from './../../_interface/index'
+
+export const rob = (root: I_TreeNode) => {
+  const money = dfs(root)
+  return Math.max(money[0], money[1])
+}
+
+function dfs(root: I_TreeNode): number[] {
+  if (!root) return [0, 0]
+  const L = dfs(root.left)
+  const R = dfs(root.right)
+  return [Math.max(L[0], L[1]) + Math.max(R[0], R[1]), root.val + L[0] + R[0]]
+}

src/trees/houseRobber3/test.ts

@@ -0,0 +1,22 @@
+import { rob } from '.'
+import { TREE_1, TREE_3, TREE_5, TREE_7, TREE_9 } from '../_testData'
+
+test('HouseRobber3', () => {
+  expect(rob(TREE_1)).toBe(8)
+})
+
+test('HouseRobber3', () => {
+  expect(rob(TREE_3)).toBe(23)
+})
+
+test('HouseRobber3', () => {
+  expect(rob(TREE_5)).toBe(0)
+})
+
+test('HouseRobber3', () => {
+  expect(rob(TREE_7)).toBe(18)
+})
+
+test('HouseRobber3', () => {
+  expect(rob(TREE_9)).toBe(4)
+})

src/trees/index.ts

@@ -18,3 +18,4 @@ export * from './twoSum4'
 export * from './maximumDepthOfBinaryTree'
 export * from './findLargestvalueInEachTreeRow'
 export * from './balancedBinaryTree'
+export * from './houseRobber3'