单调队列50分WA求助

WA on #1,3,4,5,10

#include<bits/stdc++.h>
#define ll long long
using namespace std;
mt19937 myrand(time(0));
inline ll read(){
    ll x=0,w=1;
    char ch=0;
    while(ch<'0'||ch>'9'){
        if(ch=='-')w=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9'){
        x=x*10+(ch-'0');
        ch=getchar();
    }
    return x*w;
}
void write(ll x){
    if(x<0){
        putchar('-');
        x=-x;
    }
    static int sta[35];
    int top=0;
    do{
        sta[top++]=x%10,x/=10;
    }while(x);
    while(top)putchar(sta[--top]+'0');
    putchar('\n');
}
deque<ll>q;
int n,m,a[2000005];
main(){
    n=read();m=read();
    for(int i=1;i<=n;i++)a[i]=read();
    for(int i=1;i<=n;i++){
        if(q.empty())write(0);
        else write(q.back());
        if(q.size()>=m)q.pop_back();
        while(a[i]<q.front()&&!q.empty())q.pop_front();
        q.push_front(a[i]);
    }
    return 0;
}