Merge pull request #1186 from 0xff-dev/337

Add solution and test-cases for problem 337

Author: 6boris

leetcode/301-400/0337.House-Robber-III/1.jpg

@@ -1,28 +1,30 @@
 # [337.House Robber III][title]
 
-> [!WARNING|style:flat]
-> This question is temporarily unanswered if you have good ideas. Welcome to [Create Pull Request PR](https://github.com/kylesliu/awesome-golang-algorithm)
-
 ## Description
+The thief has found himself a new place for his thievery again. There is only one entrance to this area, called `root`.
 
-**Example 1:**
+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 form a binary tree. It will automatically contact the police if **two directly-linked houses were broken into on the same night**.
 
-```
-Input: a = "11", b = "1"
-Output: "100"
-```
+Given the `root` of the binary tree, return the maximum amount of money the thief can rob **without alerting the police**.
 
-## 题意
-> ...
+**Example 1:**  
 
-## 题解
+![1](./1.jpg)
 
-### 思路1
-> ...
-House Robber III
-```go
+```
+Input: root = [3,2,3,null,3,null,1]
+Output: 7
+Explanation: Maximum amount of money the thief can rob = 3 + 3 + 1 = 7.
 ```
 
+**Example 2:**  
+
+![2](./2.jpg)
+```
+Input: root = [3,4,5,1,3,null,1]
+Output: 9
+Explanation: Maximum amount of money the thief can rob = 4 + 5 = 9.
+```
 
 ## 结语
 

leetcode/301-400/0337.House-Robber-III/2.jpg

@@ -1,5 +1,50 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+type TreeNode struct {
+	Val         int
+	Left, Right *TreeNode
+}
+
+func Solution(root *TreeNode) int {
+	cache := make(map[*TreeNode][2]int)
+	var dfs func(*TreeNode, bool) int
+	dfs = func(tree *TreeNode, selectedParent bool) int {
+		if tree == nil {
+			return 0
+		}
+		if selectedParent {
+			v, ok := cache[tree]
+			if ok {
+				if v[0] != -1 {
+					return v[0]
+				}
+			}
+			left := dfs(tree.Left, false)
+			right := dfs(tree.Right, false)
+			if !ok {
+				v = [2]int{left + right, -1}
+			} else {
+				v[0] = left + right
+			}
+			cache[tree] = v
+			return v[0]
+		}
+		v, ok := cache[tree]
+		if !ok {
+			v = [2]int{-1, -1}
+		}
+		if v[0] == -1 {
+			left := dfs(tree.Left, false)
+			right := dfs(tree.Right, false)
+			v[0] = left + right
+		}
+		if v[1] == -1 {
+			left1 := dfs(tree.Left, true)
+			right1 := dfs(tree.Right, true)
+			v[1] = left1 + right1 + tree.Val
+		}
+		cache[tree] = v
+		return max(v[0], v[1])
+	}
+	return dfs(root, false)
 }

leetcode/301-400/0337.House-Robber-III/README.md

@@ -10,12 +10,19 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs *TreeNode
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", &TreeNode{
+			Val:   3,
+			Left:  &TreeNode{Val: 2, Right: &TreeNode{Val: 3}},
+			Right: &TreeNode{Val: 3, Right: &TreeNode{Val: 1}},
+		}, 7},
+		{"TestCase2", &TreeNode{
+			Val:   3,
+			Left:  &TreeNode{Val: 4, Left: &TreeNode{Val: 1}, Right: &TreeNode{Val: 3}},
+			Right: &TreeNode{Val: 5, Right: &TreeNode{Val: 1}},
+		}, 9},
 	}
 
 	//	开始测试
@@ -30,10 +37,10 @@ func TestSolution(t *testing.T) {
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }