154. 滑动窗口【单调队列】

#include<bits/stdc++.h>
using namespace std;
const int N=1e6+10;
int a[N],n,k;
int main(void)
{
    cin>>n>>k;
    deque<int>q;
    for(int i=1;i<=n;i++) cin>>a[i];
    for(int i=1;i<=n;i++)
    {
        if(q.size()&&i-q.front()+1>k) q.pop_front();
        while(q.size()&&a[q.back()]>=a[i]) q.pop_back();
        q.push_back(i);
        if(i-k+1>=1) cout<<a[q.front()]<<" ";
    }
    puts("");
    while(q.size()) q.pop_back();
    for(int i=1;i<=n;i++)
    {
        if(q.size()&&i-q.front()+1>k) q.pop_front();
        while(q.size()&&a[q.back()]<=a[i]) q.pop_back();
        q.push_back(i);
        if(i-k+1>=1) cout<<a[q.front()]<<" ";
    }
    return 0;
}