From 3a5ba351b5fcce487f57ecbc0d694b884b27dc67 Mon Sep 17 00:00:00 2001
From: 0xff-dev <stevenshuang521@gmail.com>
Date: Wed, 16 Apr 2025 09:34:15 +0800
Subject: [PATCH] Add solution and test-cases for problem 2537
---
.../README.md | 35 +++++++++++++++++++
.../Solution.go | 23 ++++++++++--
.../Solution_test.go | 20 +++++------
3 files changed, 66 insertions(+), 12 deletions(-)
create mode 100644 leetcode/2501-2600/2537.Count-the-Number-of-Good-Subarrays/README.md
diff --git a/leetcode/2501-2600/2537.Count-the-Number-of-Good-Subarrays/README.md b/leetcode/2501-2600/2537.Count-the-Number-of-Good-Subarrays/README.md
new file mode 100644
index 000000000..fc4b8221d
--- /dev/null
+++ b/leetcode/2501-2600/2537.Count-the-Number-of-Good-Subarrays/README.md
@@ -0,0 +1,35 @@
+# [2537.Count the Number of Good Subarrays][title]
+
+## Description
+Given an integer array `nums` and an integer `k`, return the number of **good** subarrays of `nums`.
+
+A subarray `arr` is **good** if there are **at least** `k` pairs of indices `(i, j)` such that `i < j` and `arr[i] == arr[j]`.
+
+A **subarray** is a contiguous **non-empty** sequence of elements within an array.
+
+**Example 1:**
+
+```
+Input: nums = [1,1,1,1,1], k = 10
+Output: 1
+Explanation: The only good subarray is the array nums itself.
+```
+
+**Example 2:**
+
+```
+Input: nums = [3,1,4,3,2,2,4], k = 2
+Output: 4
+Explanation: There are 4 different good subarrays:
+- [3,1,4,3,2,2] that has 2 pairs.
+- [3,1,4,3,2,2,4] that has 3 pairs.
+- [1,4,3,2,2,4] that has 2 pairs.
+- [4,3,2,2,4] that has 2 pairs.
+```
+
+## 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/count-the-number-of-good-subarrays
+[me]: https://github.com/kylesliu/awesome-golang-algorithm
diff --git a/leetcode/2501-2600/2537.Count-the-Number-of-Good-Subarrays/Solution.go b/leetcode/2501-2600/2537.Count-the-Number-of-Good-Subarrays/Solution.go
index d115ccf5e..adb6c8c1d 100755
--- a/leetcode/2501-2600/2537.Count-the-Number-of-Good-Subarrays/Solution.go
+++ b/leetcode/2501-2600/2537.Count-the-Number-of-Good-Subarrays/Solution.go
@@ -1,5 +1,24 @@
package Solution
-func Solution(x bool) bool {
- return x
+func Solution(nums []int, k int) int64 {
+ l := len(nums)
+ count := make(map[int]int64)
+ start, end := 0, 0
+
+ var (
+ ans, pairs int64
+ )
+
+ i64k := int64(k)
+ for ; end < l; end++ {
+ pairs += count[nums[end]]
+ count[nums[end]]++
+
+ for ; start < end && pairs >= i64k; start++ {
+ ans += int64(l - end)
+ count[nums[start]]--
+ pairs -= count[nums[start]]
+ }
+ }
+ return ans
}
diff --git a/leetcode/2501-2600/2537.Count-the-Number-of-Good-Subarrays/Solution_test.go b/leetcode/2501-2600/2537.Count-the-Number-of-Good-Subarrays/Solution_test.go
index 14ff50eb4..69720b102 100755
--- a/leetcode/2501-2600/2537.Count-the-Number-of-Good-Subarrays/Solution_test.go
+++ b/leetcode/2501-2600/2537.Count-the-Number-of-Good-Subarrays/Solution_test.go
@@ -10,30 +10,30 @@ func TestSolution(t *testing.T) {
// 测试用例
cases := []struct {
name string
- inputs bool
- expect bool
+ nums []int
+ k int
+ expect int64
}{
- {"TestCase", true, true},
- {"TestCase", true, true},
- {"TestCase", false, false},
+ {"TestCase1", []int{1, 1, 1, 1, 1}, 10, 1},
+ {"TestCase2", []int{3, 1, 4, 3, 2, 2, 4}, 2, 4},
}
// 开始测试
for i, c := range cases {
t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
- got := Solution(c.inputs)
+ got := Solution(c.nums, c.k)
if !reflect.DeepEqual(got, c.expect) {
- t.Fatalf("expected: %v, but got: %v, with inputs: %v",
- c.expect, got, c.inputs)
+ t.Fatalf("expected: %v, but got: %v, with inputs: %v %v",
+ c.expect, got, c.nums, c.k)
}
})
}
}
-// 压力测试
+// 压力测试
func BenchmarkSolution(b *testing.B) {
}
-// 使用案列
+// 使用案列
func ExampleSolution() {
}