Add solution and test-cases for problem 2049

Author: 0xff-dev

leetcode/2001-2100/2049.Count-Nodes-With-the-Highest-Score/1.png

@@ -1,28 +1,41 @@
 # [2049.Count Nodes With the Highest Score][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
+There is a **binary** tree rooted at `0` consisting of `n` nodes. The nodes are labeled from `0` to `n - 1`. You are given a **0-indexed** integer array `parents` representing the tree, where `parents[i]` is the parent of node `i`. Since node `0` is the root, `parents[0] == -1`.
+
+Each node has a **score**. To find the score of a node, consider if the node and the edges connected to it were **removed**. The tree would become one or more **non-empty** subtrees. The **size** of a subtree is the number of the nodes in it. The **score** of the node is the **product of the sizes** of all those subtrees.
+
+Return the **number** of nodes that have the **highest score**.
 
-**Example 1:**
+**Example 1:**  
+
+![1](./1.png)
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: parents = [-1,2,0,2,0]
+Output: 3
+Explanation:
+- The score of node 0 is: 3 * 1 = 3
+- The score of node 1 is: 4 = 4
+- The score of node 2 is: 1 * 1 * 2 = 2
+- The score of node 3 is: 4 = 4
+- The score of node 4 is: 4 = 4
+The highest score is 4, and three nodes (node 1, node 3, and node 4) have the highest score.
 ```
 
-## 题意
-> ...
+**Example 2:**  
 
-## 题解
+![2](./2.png)
 
-### 思路1
-> ...
-Count Nodes With the Highest Score
-```go
 ```
-
+Input: parents = [-1,2,0]
+Output: 2
+Explanation:
+- The score of node 0 is: 2 = 2
+- The score of node 1 is: 2 = 2
+- The score of node 2 is: 1 * 1 = 1
+The highest score is 2, and two nodes (node 0 and node 1) have the highest score.
+```
 
 ## 结语
 

leetcode/2001-2100/2049.Count-Nodes-With-the-Highest-Score/2.png

@@ -1,5 +1,59 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(parents []int) int {
+	adj := make(map[int][]int)
+	for c, f := range parents {
+		adj[f] = append(adj[f], c)
+	}
+	n := len(parents)
+	children := make([][2]int, n)
+	var dfs func(int) int
+	dfs = func(root int) int {
+		children[root] = [2]int{-1, -1}
+		index := 0
+		count := 0
+		for _, child := range adj[root] {
+			children[root][index] = dfs(child)
+			count += children[root][index]
+			index++
+		}
+		return count + 1
+	}
+	_ = dfs(0)
+	ans := 0
+	// 尝试移除0
+	left := children[0][0]
+	if left == -1 {
+		left = 1
+	}
+	right := children[0][1]
+	if right == -1 {
+		right = 1
+	}
+	ans = left * right
+	count := 1
+	for i := 1; i < n; i++ {
+		x := n
+		x--
+		left = children[i][0]
+		right = children[i][1]
+		if left != -1 {
+			x -= left
+		} else {
+			left = 1
+		}
+		if right != -1 {
+			x -= right
+		} else {
+			right = 1
+		}
+		now := left * right * x
+		if now == ans {
+			count++
+		} else if now > ans {
+			ans = now
+			count = 1
+		}
+	}
+	return count
 }

leetcode/2001-2100/2049.Count-Nodes-With-the-Highest-Score/README.md

@@ -10,12 +10,11 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs []int
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{-1, 2, 0, 2, 0}, 3},
+		{"TestCase2", []int{-1, 2, 0}, 2},
 	}
 
 	//	开始测试
@@ -30,10 +29,10 @@ 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() {
 }