<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:
    vector<int> maxSlidingWindow(vector<int>& nums, int k) {
        unordered_map<int, int> map;
        int current_max = INT_MIN;
        std::vector<int> result;

        for (int i = 0; i < k; ++i) {
            map[nums[i]]++;
            current_max = max(nums[i], current_max);
        }

        result.push_back(current_max);

        for (int i = k; i < nums.size(); ++i) {
            map[nums[i - k]]--;
            map[nums[i]]++;

            if (nums[i] > current_max) {
                current_max = nums[i];
            } 
            if (map[current_max] == 0) {
                current_max = INT_MIN;
                std::vector<int> keys_to_erase;
                for (auto pair : map) {
                    if (pair.second > 0) {
                        current_max = max(current_max, pair.first);
                    } else {
                        keys_to_erase.push_back(pair.first);
                    }
                }

                for (auto key : keys_to_erase) {
                    map.erase(key);
                }
            }

            result.push_back(current_max);
        }

        return result;
    }
};

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