Merge pull request 6boris#1283 from 0xff-dev/2574

Add solution and test-cases for problem 2574

Author: 6boris

leetcode/2501-2600/2574.Left-and-Right-Sum-Differences/README.md

@@ -0,0 +1,36 @@
+# [2574.Left and Right Sum Differences][title]
+
+## Description
+You are given a **0-indexed** integer array `nums` of size `n`.
+
+Define two arrays `leftSum` and `rightSum` where:
+
+- `leftSum[i]` is the sum of elements to the left of the index `i` in the array `nums`. If there is no such element, `leftSum[i] = 0`.
+- `rightSum[i]` is the sum of elements to the right of the index `i` in the array `nums`. If there is no such element, `rightSum[i] = 0`.
+
+Return an integer array `answer` of size n where `answer[i] = |leftSum[i] - rightSum[i]|`.
+
+**Example 1:**
+
+```
+Input: nums = [10,4,8,3]
+Output: [15,1,11,22]
+Explanation: The array leftSum is [0,10,14,22] and the array rightSum is [15,11,3,0].
+The array answer is [|0 - 15|,|10 - 11|,|14 - 3|,|22 - 0|] = [15,1,11,22].
+```
+
+**Example 2:**
+
+```
+Input: nums = [1]
+Output: [0]
+Explanation: The array leftSum is [0] and the array rightSum is [0].
+The array answer is [|0 - 0|] = [0].
+```
+
+## 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/left-and-right-sum-differences
+[me]: https://github.com/kylesliu/awesome-golang-algorithm

leetcode/2501-2600/2574.Left-and-Right-Sum-Differences/Solution.go

@@ -1,5 +1,20 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(nums []int) []int {
+	n := len(nums)
+	left, right := make([]int, n), make([]int, n)
+	left[0], right[n-1] = 0, 0
+	for i := 0; i < n-1; i++ {
+		left[i+1] = nums[i] + left[i]
+	}
+	for i := n - 1; i > 0; i-- {
+		right[i-1] = right[i] + nums[i]
+	}
+	for i := 0; i < n; i++ {
+		left[i] -= right[i]
+		if left[i] < 0 {
+			left[i] = -left[i]
+		}
+	}
+	return left
 }

leetcode/2501-2600/2574.Left-and-Right-Sum-Differences/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{10, 4, 8, 3}, []int{15, 1, 11, 22}},
+		{"TestCase2", []int{1}, []int{0}},
 	}
 
 	//	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() {
 }