1793. Maximum Score of a Good Subarray

Problem Link

Description

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You are given an array of integers nums (0-indexed) and an integer k.

The score of a subarray (i, j) is defined as min(nums[i], nums[i+1], ..., nums[j]) * (j - i + 1). A good subarray is a subarray where i <= k <= j.

Return the maximum possible score of a good subarray.

 

Example 1:

Input: nums = [1,4,3,7,4,5], k = 3
Output: 15
Explanation: The optimal subarray is (1, 5) with a score of min(4,3,7,4,5) * (5-1+1) = 3 * 5 = 15. 

Example 2:

Input: nums = [5,5,4,5,4,1,1,1], k = 0
Output: 20
Explanation: The optimal subarray is (0, 4) with a score of min(5,5,4,5,4) * (4-0+1) = 4 * 5 = 20.

 

Constraints:

• 1 <= nums.length <= 105
• 1 <= nums[i] <= 2 * 104
• 0 <= k < nums.length

Solution

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Python3

class Solution:
    def maximumScore(self, nums: List[int], k: int) -> int:
        N = len(nums)
        i, j = k - 1, k + 1
        res = min_num = nums[k]
        
        while i >= 0 or j < N:
            left = nums[i] if i >= 0 else 0
            right = nums[j] if j < N else 0
 
            if left < right:
                min_num = min(min_num, right)
                j += 1
            else:
                min_num = min(min_num, left)
                i -= 1
            
            res = max(res, (j - i - 1) * min_num)
 
        return res