Merge pull request #1082 from 0xff-dev/2270

Add solution and test-cases for problem 2270

Author: 6boris

leetcode/2201-2300/2270.Number-of-Ways-to-Split-Array/README.md

@@ -1,28 +1,39 @@
 # [2270.Number of Ways to Split 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` of length `n`.
+
+`nums` contains a **valid split** at index `i` if the following are true:
+
+- The sum of the first `i + 1` elements is **greater than or equal to** the sum of the last `n - i - 1` elements.
+- There is **at least one** element to the right of `i`. That is, `0 <= i < n - 1`.
+
+Return the number of **valid splits** in `nums`.
+
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: nums = [10,4,-8,7]
+Output: 2
+Explanation: 
+There are three ways of splitting nums into two non-empty parts:
+- Split nums at index 0. Then, the first part is [10], and its sum is 10. The second part is [4,-8,7], and its sum is 3. Since 10 >= 3, i = 0 is a valid split.
+- Split nums at index 1. Then, the first part is [10,4], and its sum is 14. The second part is [-8,7], and its sum is -1. Since 14 >= -1, i = 1 is a valid split.
+- Split nums at index 2. Then, the first part is [10,4,-8], and its sum is 6. The second part is [7], and its sum is 7. Since 6 < 7, i = 2 is not a valid split.
+Thus, the number of valid splits in nums is 2.
 ```
 
-## 题意
-> ...
-
-## 题解
+**Example 2:**
 
-### 思路1
-> ...
-Number of Ways to Split Array
-```go
 ```
-
+Input: nums = [2,3,1,0]
+Output: 2
+Explanation: 
+There are two valid splits in nums:
+- Split nums at index 1. Then, the first part is [2,3], and its sum is 5. The second part is [1,0], and its sum is 1. Since 5 >= 1, i = 1 is a valid split. 
+- Split nums at index 2. Then, the first part is [2,3,1], and its sum is 6. The second part is [0], and its sum is 0. Since 6 >= 0, i = 2 is a valid split.
+```
 
 ## 结语
 

leetcode/2201-2300/2270.Number-of-Ways-to-Split-Array/Solution.go

@@ -1,5 +1,15 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(nums []int) int {
+	ans := 0
+	l := len(nums)
+	for i := 1; i < l; i++ {
+		nums[i] += nums[i-1]
+	}
+	for i := 0; i < l-1; i++ {
+		if nums[i] >= nums[l-1]-nums[i] {
+			ans++
+		}
+	}
+	return ans
 }

leetcode/2201-2300/2270.Number-of-Ways-to-Split-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 int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{10, 4, -8, 7}, 2},
+		{"TestCase2", []int{2, 3, 1, 0}, 2},
 	}
 
 	//	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() {
 }