Merge pull request #1146 from 0xff-dev/2640

Add solution and test-cases for problem 2640

Author: 6boris

leetcode/2601-2700/2640.Find-the-Score-of-All-Prefixes-of-an-Array/README.md

@@ -0,0 +1,45 @@
+# [2640.Find the Score of All Prefixes of an Array][title]
+
+## Description
+
+We define the **conversion array** `conver` of an array `arr` as follows:
+
+- `conver[i] = arr[i] + max(arr[0..i])` where `max(arr[0..i])` is the maximum value of `arr[j]` over `0 <= j <= i`.
+
+We also define the **score** of an array `arr` as the sum of the values of the conversion array of `arr`.
+
+Given a **0-indexed** integer array `nums` of length n, return an array `ans` of length `n` where `ans[i]` is the score of the prefix `nums[0..i]`.
+
+**Example 1:**
+
+```
+Input: nums = [2,3,7,5,10]
+Output: [4,10,24,36,56]
+Explanation: 
+For the prefix [2], the conversion array is [4] hence the score is 4
+For the prefix [2, 3], the conversion array is [4, 6] hence the score is 10
+For the prefix [2, 3, 7], the conversion array is [4, 6, 14] hence the score is 24
+For the prefix [2, 3, 7, 5], the conversion array is [4, 6, 14, 12] hence the score is 36
+For the prefix [2, 3, 7, 5, 10], the conversion array is [4, 6, 14, 12, 20] hence the score is 56
+```
+
+**EXample 2:**
+
+```
+Input: nums = [1,1,2,4,8,16]
+Output: [2,4,8,16,32,64]
+Explanation: 
+For the prefix [1], the conversion array is [2] hence the score is 2
+For the prefix [1, 1], the conversion array is [2, 2] hence the score is 4
+For the prefix [1, 1, 2], the conversion array is [2, 2, 4] hence the score is 8
+For the prefix [1, 1, 2, 4], the conversion array is [2, 2, 4, 8] hence the score is 16
+For the prefix [1, 1, 2, 4, 8], the conversion array is [2, 2, 4, 8, 16] hence the score is 32
+For the prefix [1, 1, 2, 4, 8, 16], the conversion array is [2, 2, 4, 8, 16, 32] hence the score is 64
+```
+
+## 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/find-the-score-of-all-prefixes-of-an-array
+[me]: https://github.com/kylesliu/awesome-golang-algorithm

leetcode/2601-2700/2640.Find-the-Score-of-All-Prefixes-of-an-Array/Solution.go

@@ -1,5 +1,12 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(nums []int) []int64 {
+	ans := make([]int64, len(nums))
+	m := int64(nums[0])
+	ans[0] = int64(nums[0]) + m
+	for i := 1; i < len(nums); i++ {
+		m = max(m, int64(nums[i]))
+		ans[i] = int64(nums[i]) + m + ans[i-1]
+	}
+	return ans
 }

leetcode/2601-2700/2640.Find-the-Score-of-All-Prefixes-of-an-Array/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 []int64
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{2, 3, 7, 5, 10}, []int64{4, 10, 24, 36, 56}},
+		{"TestCase2", []int{1, 1, 2, 4, 8, 16}, []int64{2, 4, 8, 16, 32, 64}},
 	}
 
 	//	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() {
 }