萌新刚学单调队列，咋就tle70分呢

#include<iostream>
#include<deque>
#include<queue>
using namespace std;
long long n,m,mn = 99999999;
struct element{
    long long v,id;
};
deque<element> a;
int main(){
    cin>>n>>m;
    a.push_back({99999999,0});
    cout<<0<<endl;
    for(long long i = 1;i<n;i++){
        long long x;
        cin>>x;
        if(x<a.back().v){
            while(!a.empty()&&x<a.back().v){
                a.pop_back();
            }
        }
        a.push_back({x,i});
        cout<<a.front().v<<endl;
        if(a.front().id==i-m+1)a.pop_front();
    }
    return 0;
}