Merge pull request #882 from 0xff-dev/2491

Add solution and test-cases for problem 2491

Author: 6boris

leetcode/2401-2500/2491.Divide-Players-Into-Teams-of-Equal-Skill/README.md

@@ -1,28 +1,40 @@
 # [2491.Divide Players Into Teams of Equal Skill][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
+You are given a positive integer array `skill` of **even** length `n` where `skill[i]` denotes the skill of the i<sup>th</sup>. player. Divide the players into `n / 2` teams of size `2` such that the total skill of each team is **equal**.
+
+The **chemistry** of a team is equal to the **product** of the skills of the players on that team.
+
+Return the sum of the *chemistry** of all the teams, or return `-1` if there is no way to divide the players into teams such that the total skill of each team is equal.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: skill = [3,2,5,1,3,4]
+Output: 22
+Explanation: 
+Divide the players into the following teams: (1, 5), (2, 4), (3, 3), where each team has a total skill of 6.
+The sum of the chemistry of all the teams is: 1 * 5 + 2 * 4 + 3 * 3 = 5 + 8 + 9 = 22.
 ```
 
-## 题意
-> ...
-
-## 题解
+**Example 2:**
 
-### 思路1
-> ...
-Divide Players Into Teams of Equal Skill
-```go
 ```
+Input: skill = [3,4]
+Output: 12
+Explanation: 
+The two players form a team with a total skill of 7.
+The chemistry of the team is 3 * 4 = 12.
+```
+
+**Example 3:**
 
+```
+Input: skill = [1,1,2,3]
+Output: -1
+Explanation: 
+There is no way to divide the players into teams such that the total skill of each team is equal.
+```
 
 ## 结语
 

leetcode/2401-2500/2491.Divide-Players-Into-Teams-of-Equal-Skill/Solution.go

@@ -1,5 +1,21 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+import "sort"
+
+func Solution(skill []int) int64 {
+	sort.Ints(skill)
+	cur := -1
+	ans := int64(0)
+	for s, e := 0, len(skill)-1; s < e; s, e = s+1, e-1 {
+		if cur == -1 {
+			cur = skill[s] + skill[e]
+			ans += int64(skill[s]) * int64(skill[e])
+			continue
+		}
+		if skill[s]+skill[e] != cur {
+			return -1
+		}
+		ans += int64(skill[s]) * int64(skill[e])
+	}
+	return ans
 }

leetcode/2401-2500/2491.Divide-Players-Into-Teams-of-Equal-Skill/Solution_test.go

@@ -10,12 +10,12 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs []int
+		expect int64
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{3, 2, 5, 1, 3, 4}, 22},
+		{"TestCase2", []int{3, 4}, 12},
+		{"TestCase3", []int{1, 1, 2, 3}, -1},
 	}
 
 	//	开始测试
@@ -30,10 +30,10 @@ 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() {
 }