<p>You are given an array of integers&nbsp;<code>nums</code>, there is a sliding window of size <code>k</code> which is moving from the very left of the array to the very right. You can only see the <code>k</code> numbers in the window. Each time the sliding window moves right by one position.</p>

<p>Return <em>the max sliding window</em>.</p>

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

<pre>
<strong>Input:</strong> nums = [1,3,-1,-3,5,3,6,7], k = 3
<strong>Output:</strong> [3,3,5,5,6,7]
<strong>Explanation:</strong> 
Window position                Max
---------------               -----
[1  3  -1] -3  5  3  6  7       <strong>3</strong>
 1 [3  -1  -3] 5  3  6  7       <strong>3</strong>
 1  3 [-1  -3  5] 3  6  7      <strong> 5</strong>
 1  3  -1 [-3  5  3] 6  7       <strong>5</strong>
 1  3  -1  -3 [5  3  6] 7       <strong>6</strong>
 1  3  -1  -3  5 [3  6  7]      <strong>7</strong>
</pre>

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

<pre>
<strong>Input:</strong> nums = [1], k = 1
<strong>Output:</strong> [1]
</pre>

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

<ul>
	<li><code>1 &lt;= nums.length &lt;= 10<sup>5</sup></code></li>
	<li><code>-10<sup>4</sup> &lt;= nums[i] &lt;= 10<sup>4</sup></code></li>
	<li><code>1 &lt;= k &lt;= nums.length</code></li>
</ul>

class Solution {
public:
    class Queue {
        private:
            const size_t size;
            int* arr;
            int front;
            map<int, int> arrMap;
        public:
            Queue(const size_t &sizeP): size(sizeP), front(0), arr(new int[size]()) {}
            ~Queue() {delete[] arr;}
            void add(const int &e) {
                arrMap[arr[front]]--;
                if (arrMap[arr[front]] <= 0) arrMap.erase(arr[front]);
                arrMap[e]++;

                arr[front] = e;
                
                front = (front + 1) % size;
            }

            int max() {
                return arrMap.rbegin()->first;
            }

            // void print() {
            //     for (int i = 0; i < size; ++i) {
            //         cout << arr[i] << " ";
            //     }
            //     cout << endl;
            // }

            // void printMap(){
            //     for (const auto& pair : arrMap) {
            //         cout << "{" << pair.first << ": " << pair.second << "} ";
            //     }
            //     cout << endl;
            // }

    };

    vector<int> maxSlidingWindow(vector<int>& nums, int k) {
        int size = nums.size();
        vector<int> maxResults;
        Queue queue(k);

        for (int i = 0; i < k; ++i) {
            queue.add(nums[i]);
            // queue.print();
            // queue.printMap();
        }

        maxResults.push_back(queue.max());

        for (int i = k; i < size; ++i) {
            queue.add(nums[i]);
            // queue.print();
            // queue.printMap();
            maxResults.push_back(queue.max());
        }
        return maxResults;
    }
};
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