Merge pull request #1133 from 0xff-dev/1749

Add solution and test-cases for problem 1749

Author: 6boris

leetcode/1701-1800/1749.Maximum-Absolute-Sum-of-Any-Subarray/README.md

@@ -1,28 +1,30 @@
 # [1749.Maximum Absolute Sum of Any 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 integer array nums. The **absolute sum** of a subarray `[numsl, numsl+1, ..., numsr-1, numsr]` is `abs(numsl + numsl+1 + ... + numsr-1 + numsr)`.
+
+Return the **maximum** absolute sum of any **(possibly empty)** subarray of `nums`.
+
+Note that `abs(x)` is defined as follows:
+
+- If `x` is a negative integer, then `abx(x) = -x`.
+- If `x` is a non-negative integer, then `abs(x) = x`.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: nums = [1,-3,2,3,-4]
+Output: 5
+Explanation: The subarray [2,3] has absolute sum = abs(2+3) = abs(5) = 5.
 ```
 
-## 题意
-> ...
+**Example 2:**
 
-## 题解
-
-### 思路1
-> ...
-Maximum Absolute Sum of Any Subarray
-```go
 ```
-
+Input: nums = [2,-5,1,-4,3,-2]
+Output: 8
+Explanation: The subarray [-5,1,-4] has absolute sum = abs(-5+1-4) = abs(-8) = 8.
+```
 
 ## 结语
 

leetcode/1701-1800/1749.Maximum-Absolute-Sum-of-Any-Subarray/Solution.go

@@ -1,5 +1,24 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(nums []int) int {
+	ans := 0
+	_max, _min := 0, 0 //最大的正数，最小的负数
+	sum := 0
+	for _, n := range nums {
+		cur := n
+		if cur < 0 {
+			cur = -n
+		}
+		ans = max(ans, cur)
+		sum += n
+		if sum >= 0 {
+			cur = sum - _min
+			_max = max(_max, sum)
+		} else {
+			cur = -(sum - _max)
+			_min = min(_min, sum)
+		}
+		ans = max(ans, cur)
+	}
+	return ans
 }

leetcode/1701-1800/1749.Maximum-Absolute-Sum-of-Any-Subarray/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{1, -3, 2, 3, -4}, 5},
+		{"TestCase2", []int{2, -5, 1, -4, 3, -2}, 8},
 	}
 
 	//	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() {
 }