Sliding Window Maximum

Author: TonyStark-19

Queue/SlidingWindowMaximum.cpp

@@ -0,0 +1,62 @@
+#include <iostream>
+#include <deque>
+#include <vector>
+using namespace std;
+// using deque
+
+vector<int> maxSlidingWindow(vector<int> &nums, int k)
+{
+    deque<int> dq;
+    vector<int> res;
+
+    // first window
+
+    for (int i = 0; i < k; i++)
+    {
+        // delete smaller value
+        while (dq.size() > 0 && nums[dq.back()] <= nums[i])
+        {
+            dq.pop_back();
+        }
+        // push new index values
+        dq.push_back(i);
+    }
+
+    for (int i = k; i < nums.size(); i++)
+    {
+        res.push_back(nums[dq.front()]);
+
+        // remove elements not part of current window
+        while (dq.size() > 0 && dq.front() <= i - k)
+        {
+            dq.pop_front();
+        }
+
+        // delete smaller value
+        while (dq.size() > 0 && nums[dq.back()] <= nums[i])
+        {
+            dq.pop_back();
+        }
+
+        dq.push_back(i);
+    }
+
+    res.push_back(nums[dq.front()]);
+    return res;
+}
+
+int main()
+{
+    vector<int> nums = {1, 3, -1, -3, 5, 3, 6, 7};
+    int k = 3;
+
+    vector<int> ans = maxSlidingWindow(nums, k);
+
+    for (int val : ans)
+    {
+        cout << val << " ";
+    }
+    cout << endl;
+
+    return 0;
+}