Merge pull request #901 from 0xff-dev/3068

Add solution and test-cases for problem 3068

leetcode/3001-3100/3068.Find-the-Maximum-Sum-of-Node-Values/README.md

@@ -1,28 +1,52 @@
 # [3068.Find the Maximum Sum of Node Values][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 exists an **undirected** tree with `n` nodes numbered `0` to `n - 1`. You are given a **0-indexed** 2D integer array `edges` of length `n - 1`, where `edges[i] = [ui, vi]` indicates that there is an edge between nodes u<sub>i</sub> and v<sub>i</sub> in the tree. You are also given a **positive** integer `k`, and a **0-indexed** array of **non-negative** integers `nums` of length `n`, where `nums[i]` represents the **value** of the node numbered `i`.
+
+Alice wants the sum of values of tree nodes to be **maximum**, for which Alice can perform the following operation **any** number of times (**including zero**) on the tree:
+
+- Choose any edge `[u, v]` connecting the nodes `u` and `v`, and update their values as follows:
+
+    - `nums[u] = nums[u] XOR k`
+    - `nums[v] = nums[v] XOR k`
+
+Return the **maximum** possible **sum** of the **values** Alice can achieve by performing the operation **any** number of times.
+
+**Example 1:**  
 
-**Example 1:**
+![1](./screenshot-2023-11-10-012513.png)
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: nums = [1,2,1], k = 3, edges = [[0,1],[0,2]]
+Output: 6
+Explanation: Alice can achieve the maximum sum of 6 using a single operation:
+- Choose the edge [0,2]. nums[0] and nums[2] become: 1 XOR 3 = 2, and the array nums becomes: [1,2,1] -> [2,2,2].
+The total sum of values is 2 + 2 + 2 = 6.
+It can be shown that 6 is the maximum achievable sum of values.
 ```
 
-## 题意
-> ...
+**Example 2:**  
 
-## 题解
+![2](./screenshot-2024-01-09-220017.png)
 
-### 思路1
-> ...
-Find the Maximum Sum of Node Values
-```go
 ```
+Input: nums = [2,3], k = 7, edges = [[0,1]]
+Output: 9
+Explanation: Alice can achieve the maximum sum of 9 using a single operation:
+- Choose the edge [0,1]. nums[0] becomes: 2 XOR 7 = 5 and nums[1] become: 3 XOR 7 = 4, and the array nums becomes: [2,3] -> [5,4].
+The total sum of values is 5 + 4 = 9.
+It can be shown that 9 is the maximum achievable sum of values.
+```
+
+**Example 3:**  
+
+![3](./screenshot-2023-11-10-012641.png)
 
+```
+Input: nums = [7,7,7,7,7,7], k = 3, edges = [[0,1],[0,2],[0,3],[0,4],[0,5]]
+Output: 42
+Explanation: The maximum achievable sum is 42 which can be achieved by Alice performing no operations.
+```
 
 ## 结语
 

leetcode/3001-3100/3068.Find-the-Maximum-Sum-of-Node-Values/Solution.go

@@ -1,5 +1,29 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+import "sort"
+
+func Solution(nums []int, k int, edges [][]int) int64 {
+	// 经过测试，[0,1],[1,2] [1,2,1]这组数据也是6，就是说他选的任何节点俩节点，都可以
+	// 那么我们关注的就是，最大值从小大排列， 而且题目保证了是一棵树，
+	// 所以，只需要每次选俩和是正的就ok
+
+	diff := make([]int, len(nums))
+	ans := int64(0)
+	for i, v := range nums {
+		ans += int64(v)
+		diff[i] = v ^ k - v
+	}
+
+	sort.Slice(diff, func(i, j int) bool {
+		return diff[i] > diff[j]
+	})
+	for i := 0; i < len(diff); i += 2 {
+		if i+1 == len(diff) {
+			break
+		}
+		if s := int64(diff[i]) + int64(diff[i+1]); s > 0 {
+			ans += s
+		}
+	}
+	return ans
 }

leetcode/3001-3100/3068.Find-the-Maximum-Sum-of-Node-Values/Solution_test.go

@@ -10,30 +10,31 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		nums   []int
+		edges  [][]int
+		k      int
+		expect int64
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{1, 2, 1}, [][]int{{0, 1}, {0, 2}}, 3, 6},
+		{"TestCase2", []int{2, 3}, [][]int{{0, 1}}, 7, 9},
 	}
 
 	//	开始测试
 	for i, c := range cases {
 		t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
-			got := Solution(c.inputs)
+			got := Solution(c.nums, c.k, c.edges)
 			if !reflect.DeepEqual(got, c.expect) {
-				t.Fatalf("expected: %v, but got: %v, with inputs: %v",
-					c.expect, got, c.inputs)
+				t.Fatalf("expected: %v, but got: %v, with inputs: %v %v %v",
+					c.expect, got, c.nums, c.edges, c.k)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }