Merge pull request #1321 from 0xff-dev/2012

Add solution and test-cases for problem 2012

Author: 6boris

leetcode/2001-2100/2012.Sum-of-Beauty-in-the-Array/README.md

@@ -1,28 +1,41 @@
 # [2012.Sum of Beauty in the Array][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 **0-indexed** integer array nums. For each index `i` (`1 <= i <= nums.length - 2`) the **beauty** of `nums[i]` equals:
+
+- `2`, if `nums[j] < nums[i] < nums[k]`, for **all** `0 <= j < i` and for **all** `i < k <= nums.length - 1`.
+- `1`, if `nums[i - 1] < nums[i] < nums[i + 1]`, and the previous condition is not satisfied.
+- `0`, if none of the previous conditions holds.
+
+Return the **sum of beauty** of all `nums[i]` where `1 <= i <= nums.length - 2`.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: nums = [1,2,3]
+Output: 2
+Explanation: For each index i in the range 1 <= i <= 1:
+- The beauty of nums[1] equals 2.
 ```
 
-## 题意
-> ...
-
-## 题解
+**Example 2:**
 
-### 思路1
-> ...
-Sum of Beauty in the Array
-```go
 ```
+Input: nums = [2,4,6,4]
+Output: 1
+Explanation: For each index i in the range 1 <= i <= 2:
+- The beauty of nums[1] equals 1.
+- The beauty of nums[2] equals 0.
+```
+
+**Example 3:**
 
+```
+Input: nums = [3,2,1]
+Output: 0
+Explanation: For each index i in the range 1 <= i <= 1:
+- The beauty of nums[1] equals 0.
+```
 
 ## 结语
 

leetcode/2001-2100/2012.Sum-of-Beauty-in-the-Array/Solution.go

@@ -1,5 +1,29 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(nums []int) int {
+	l := len(nums)
+
+	leftMax := make([]int, l)
+	rightMin := make([]int, l)
+	leftMax[0] = nums[0]
+	for i := 1; i < l; i++ {
+		leftMax[i] = max(nums[i-1], leftMax[i-1])
+	}
+	rightMin[l-1] = nums[l-1]
+	for i := l - 2; i >= 0; i-- {
+		rightMin[i] = min(rightMin[i+1], nums[i+1])
+	}
+	ret := 0
+	for i := 1; i < l-1; i++ {
+		lm := leftMax[i]
+		rm := rightMin[i]
+		if nums[i] > lm && nums[i] < rm {
+			ret += 2
+			continue
+		}
+		if nums[i] > nums[i-1] && nums[i] < nums[i+1] {
+			ret++
+		}
+	}
+	return ret
 }

leetcode/2001-2100/2012.Sum-of-Beauty-in-the-Array/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 int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{1, 2, 3}, 2},
+		{"TestCase2", []int{2, 4, 6, 4}, 1},
+		{"TestCase3", []int{3, 2, 1}, 0},
 	}
 
 	//	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() {
 }