Add solution and test-cases for problem 561

Author: 0xff-dev

leetcode/501-600/0561.Array-Partition/README.md

@@ -0,0 +1,31 @@
+# [561.Array Partition][title]
+
+## Description
+Given an integer array `nums` of `2n` integers, group these integers into `n` pairs `(a1, b1), (a2, b2), ..., (an, bn)` such that the sum of `min(ai, bi)` for all `i` is **maximized**. Return the maximized sum.
+
+**Example 1:**
+
+```
+Input: nums = [1,4,3,2]
+Output: 4
+Explanation: All possible pairings (ignoring the ordering of elements) are:
+1. (1, 4), (2, 3) -> min(1, 4) + min(2, 3) = 1 + 2 = 3
+2. (1, 3), (2, 4) -> min(1, 3) + min(2, 4) = 1 + 2 = 3
+3. (1, 2), (3, 4) -> min(1, 2) + min(3, 4) = 1 + 3 = 4
+So the maximum possible sum is 4.
+```
+
+**Example 2:**
+
+```
+Input: nums = [6,2,6,5,1,2]
+Output: 9
+Explanation: The optimal pairing is (2, 1), (2, 5), (6, 6). min(2, 1) + min(2, 5) + min(6, 6) = 1 + 2 + 6 = 9.
+```
+
+## 结语
+
+如果你同我一样热爱数据结构、算法、LeetCode，可以关注我 GitHub 上的 LeetCode 题解：[awesome-golang-algorithm][me]
+
+[title]: https://leetcode.com/problems/array-partition
+[me]: https://github.com/kylesliu/awesome-golang-algorithm

leetcode/501-600/0561.Array-Partition/Solution.go

@@ -1,5 +1,12 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+import "sort"
+
+func Solution(nums []int) int {
+	sort.Ints(nums)
+	ans := 0
+	for i := 0; i < len(nums); i += 2 {
+		ans += min(nums[i], nums[i+1])
+	}
+	return ans
 }

leetcode/501-600/0561.Array-Partition/Solution_test.go

@@ -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, 4, 3, 2}, 4},
+		{"TestCase2", []int{6, 2, 6, 5, 1, 2}, 9},
 	}
 
 	//	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() {
 }