Today I have done leetcode's October LeetCoding Challenge with cpp.

October LeetCoding Challenge 22

Description

Maximum Score of a Good Subarray

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

class Solution {
public:
  int maximumScore(vector<int>& nums, int k) {
    int left = k;
    int right = k;
    int minVal = nums[k];
    int maxScore = nums[k];

    while(left > 0 || right < nums.size() - 1) {
      if(!left || (right < nums.size() - 1 && nums[right + 1] > nums[left - 1])) {
        right += 1;
      } else {
        left -= 1;
      }

      minVal = min({minVal, nums[left], nums[right]});
      maxScore = max(maxScore, minVal * (right - left + 1));
    }

    return maxScore;
  }
};

// Accepted
// 72/72 cases passed (136 ms)
// Your runtime beats 63.82 % of cpp submissions
// Your memory usage beats 59.87 % of cpp submissions (90 MB)