1746. Maximum Subarray Sum After One Operation

https://leetcode.com/problems/maximum-subarray-sum-after-one-operation

Description

You are given an integer array nums. You must perform exactly one operation where you can replace one element nums[i] with nums[i] * nums[i].

Return the maximum possible subarray sum after exactly one operation. The subarray must be non-empty.

Example 1:

**Input:** nums = [2,-1,-4,-3]
**Output:** 17
**Explanation:** You can perform the operation on index 2 (0-indexed) to make nums = [2,-1,**16**,-3]. Now, the maximum subarray sum is 2 + -1 + 16 = 17.

Example 2:

**Input:** nums = [1,-1,1,1,-1,-1,1]
**Output:** 4
**Explanation:** You can perform the operation on index 1 (0-indexed) to make nums = [1,**1**,1,1,-1,-1,1]. Now, the maximum subarray sum is 1 + 1 + 1 + 1 = 4.

Constraints:

• 1 <= nums.length <= 105

• -104 <= nums[i] <= 104

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