sliding_window_max_of_all_subarrays.cpp

 #include <bits/stdc++.h>
 #include <deque>
 using namespace std;

 //Main Function Block
 void printKMax(int arr[], int n, int k)
 {
 	deque<int> dq(k);
 	for (int i = 0; i < k; ++i)
 	{
 		while ((!dq.empty()) && arr[i] >= arr[dq.back()])
 			dq.pop_back();

 		dq.push_back(i);
 	}

 	for (; i < n; ++i)
 	{
 		cout << arr[dq.front()] << " ";

 		while ((!dq.empty()) && dq.front() <= i - k)

 			dq.pop_front();

 		while ((!dq.empty()) && arr[i] >= arr[dq.back()])
 			dq.pop_back();

 		dq.push_back(i);
 	}

 	cout << arr[dq.front()];
 }

 //Testing code
 int main()
 {
 	int arr[] = { 12, 156, 73, 93, 59, 83, 51, 73, 101, 456};
 	int n = sizeof(arr) / sizeof(arr[0]);
 	int k = 3;
 	printKMax(arr, n, k);
 	return 0;
 }