<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>

#pragma GCC optimize("Ofast")
#pragma GCC target("arch=native")
class Solution {
    using out_t = std::vector<int>;

    static bool init() noexcept 
    {
        ios::sync_with_stdio(0);
        cin.tie(0);
        return true;
    }
    static inline bool initialized = init();

public:
    out_t maxSlidingWindow(vector<int>& nums, const int k) const noexcept {
        const auto n = nums.size() + 1 - k;
        std::deque<int> q;

        q.push_back(0);
        for (int i = 1; i < k; ++i)
        {
            const auto x = nums[i];
            while (!q.empty() && x >= nums[q.back()]) {
                q.pop_back();
            }
            q.push_back(i);
        }
        nums[0] = nums[q.front()];
        
        for (int i = 1; i < n; ++i)
        {
            if (q.front() < i) {
                q.pop_front();
            }

            const int j = i + k - 1;
            const auto x = nums[j];
            while (!q.empty() && x >= nums[q.back()]) {
                q.pop_back();
            }
            q.push_back(j);

            nums[i] = nums[q.front()];
        }

        nums.resize(n);

        return std::move(nums);
    }
};
128738