17. Number of Subarrays with Bounded Maximum.cpp

/*
Number of Subarrays with Bounded Maximum
=========================================

We are given an array nums of positive integers, and two positive integers left and right (left <= right).

Return the number of (contiguous, non-empty) subarrays such that the value of the maximum array element in that subarray is at least left and at most right.

Example:
Input: 
nums = [2, 1, 4, 3]
left = 2
right = 3
Output: 3
Explanation: There are three subarrays that meet the requirements: [2], [2, 1], [3].
Note:

left, right, and nums[i] will be an integer in the range [0, 109].
The length of nums will be in the range of [1, 50000].
*/

class Solution
{
public:
  int numSubarrayBoundedMax(vector<int> &nums, int left, int right)
  {
    int ans = 0;
    int i = 0, j = 0, count = 0;

    while (j < nums.size())
    {
      if (nums[j] >= left && nums[j] <= right)
      {
        count = (j - i + 1);
        ans += count;
      }
      else if (nums[j] < left)
        ans += count;
      else
      {
        i = j + 1;
        count = 0;
      }
      j++;
    }
    return ans;
  }
};