Merge pull request #1111 from 0xff-dev/3105

Add solution and test-cases for problem 3105

Author: 6boris

leetcode/3101-3200/3105.Longest-Strictly-Increasing-or-Strictly-Decreasing-Subarray/README.md

@@ -1,28 +1,55 @@
 # [3105.Longest Strictly Increasing or Strictly Decreasing Subarray][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 an array of integers `nums`. Return the length of the **longest** subarray of `nums` which is either strictly increasing or strictly decreasing
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: nums = [1,4,3,3,2]
+
+Output: 2
+
+Explanation:
+
+The strictly increasing subarrays of nums are [1], [2], [3], [3], [4], and [1,4].
+
+The strictly decreasing subarrays of nums are [1], [2], [3], [3], [4], [3,2], and [4,3].
+
+Hence, we return 2.
+```
+
+**Example 2:**
+
 ```
+Input: nums = [3,3,3,3]
+
+Output: 1
 
-## 题意
-> ...
+Explanation:
 
-## 题解
+The strictly increasing subarrays of nums are [3], [3], [3], and [3].
 
-### 思路1
-> ...
-Longest Strictly Increasing or Strictly Decreasing Subarray
-```go
+The strictly decreasing subarrays of nums are [3], [3], [3], and [3].
+
+Hence, we return 1.
 ```
 
+**Example 3:**
+
+```
+Input: nums = [3,2,1]
+
+Output: 3
+
+Explanation:
+
+The strictly increasing subarrays of nums are [3], [2], and [1].
+
+The strictly decreasing subarrays of nums are [3], [2], [1], [3,2], [2,1], and [3,2,1].
+
+Hence, we return 3.
+```
 
 ## 结语
 

leetcode/3101-3200/3105.Longest-Strictly-Increasing-or-Strictly-Decreasing-Subarray/Solution.go

@@ -1,5 +1,25 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func helper(nums []int, less func(i, j int) bool) int {
+	l := 1
+	res := 1
+	for i := 1; i < len(nums); i++ {
+		if less(nums[i-1], nums[i]) {
+			l++
+			res = max(res, l)
+			continue
+		}
+		l = 1
+	}
+	return max(res, l)
+}
+
+func Solution(nums []int) int {
+	a := helper(nums, func(i, j int) bool {
+		return i < j
+	})
+	b := helper(nums, func(i, j int) bool {
+		return i > j
+	})
+	return max(a, b)
 }

leetcode/3101-3200/3105.Longest-Strictly-Increasing-or-Strictly-Decreasing-Subarray/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, 4, 3, 3, 2}, 2},
+		{"TestCase2", []int{3, 3, 3, 3}, 1},
+		{"TestCase3", []int{3, 2, 1}, 3},
 	}
 
 	//	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() {
 }