<p>You are given an integer array <code>nums</code> and two integers <code>minK</code> and <code>maxK</code>.</p>

<p>A <strong>fixed-bound subarray</strong> of <code>nums</code> is a subarray that satisfies the following conditions:</p>

<ul>
	<li>The <strong>minimum</strong> value in the subarray is equal to <code>minK</code>.</li>
	<li>The <strong>maximum</strong> value in the subarray is equal to <code>maxK</code>.</li>
</ul>

<p>Return <em>the <strong>number</strong> of fixed-bound subarrays</em>.</p>

<p>A <strong>subarray</strong> is a <strong>contiguous</strong> part of an array.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,3,5,2,7,5], minK = 1, maxK = 5
<strong>Output:</strong> 2
<strong>Explanation:</strong> The fixed-bound subarrays are [1,3,5] and [1,3,5,2].
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,1,1,1], minK = 1, maxK = 1
<strong>Output:</strong> 10
<strong>Explanation:</strong> Every subarray of nums is a fixed-bound subarray. There are 10 possible subarrays.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>2 &lt;= nums.length &lt;= 10<sup>5</sup></code></li>
	<li><code>1 &lt;= nums[i], minK, maxK &lt;= 10<sup>6</sup></code></li>
</ul>

class Solution {
public:
    long long countSubarrays(vector<int>& nums, int minK, int maxK) {
        int n = nums.size();
        int border = n, maxIn = n, minIn = n;
        long long int ans = 0;
        if(minK == maxK){
            int last = -1;
            for(int i=0;i<n;i++){
                if(nums[i] != minK){
                    long long int len = i - last - 1;
                    ans += len*(len+1)/2;
                    last = i;
                }
            }
            long long int x = n - last - 1;
            ans += x*(x+1)/2;
            return ans;
        }
        vector<int> br(n);
        int brLeft = -1;
        for(int i=0;i<n;i++){
            if(nums[i] < minK || nums[i] > maxK)
            brLeft = i;
            else
            br[i] = brLeft;
        }
        for(int i=n-1;i>=0;i--){
            if(nums[i] < minK || nums[i] > maxK){
                //cout<<"0 ";
                border = i;
            }
            else if(nums[i] == minK){
                int x = min(minIn, border);
                if(x > maxIn)
                ans += (long long int)(i-br[i])*(long long int)(x - maxIn);
                minIn = i;
                //cout<<"1 ";
            }
            else if(nums[i] == maxK){
                int x = min(maxIn, border);
                if(x > minIn)
                ans += (long long int)(i-br[i])*(long long int)(x - minIn);
                maxIn = i;
                //cout<<"5 ";
            }
            // else
            // cout<<"2 ";
        }
        return ans;
    }
};
// [7,5,2,2,1,1,2,5,1,5,1,2,1,5,1,5,2,1]
85500