Deque

#include <cstdio>
#include <deque>
#include <algorithm>
#include <iostream>

using namespace std;

int a[1000000];
int x[1000000], y[1000000];
deque<int> dq2;

int main()
{
int T;
    cin >> T;
while(T--){
dq2.clear();
int n, k;
scanf("%d %d", &n, &k);

for (int i = 0; i < n; i++) scanf("%d", a + i);

for (int i = 0; i < k - 1; i++){

while (dq2.size() && a[dq2[dq2.size() - 1]] <= a[i]) dq2.pop_back();
dq2.push_back(i);
}

for (int i = 0, j; (j = i + k - 1) < n; i++){
while (dq2.size() && a[dq2[dq2.size() - 1]] <= a[j]) dq2.pop_back();
dq2.push_back(j);

y[i] = a[dq2[0]];
if (dq2[0] == i) dq2.pop_front();
}

for (int i = 0; i <= n - k; i++) printf("%d%c", y[i], i == n - k ? '\n' : ' ');
}
return (0);

}