poj 2823

才发现我的第一道BZ是单调队列。。

发现云神的资料里面有这个的介绍就来水水。。

单调队列由于要去掉队尾就还是用数组好点，而且写起来比STL要好看点

//#include<bits/stdc++.h>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
#include<queue>
#define inc(i,l,r) for(int i=l;i<=r;i++)
#define dec(i,l,r) for(int i=l;i>=r;i--)
#define link(x) for(edge *j=h[x];j;j=j->next)
#define mem(a) memset(a,0,sizeof(a))
#define inf 1e9
#define ll long long
#define succ(x) (1<<x)
#define NM 1000000+5
using namespace std;
int read(){
    int x=0,f=1;char ch=getchar();
    while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
    while(isdigit(ch))x=x*10+ch-'0',ch=getchar();
    return x*f;
}
int n,m,q[NM],a[NM],qh,qt,k;
int main(){
//    freopen("data.in","r",stdin);
    n=read();k=read();
    inc(i,1,n)a[i]=read();qh=1;
    inc(i,1,k-1){
        while(qh<=qt&&a[q[qt]]>=a[i])qt--;
        q[++qt]=i;
    }
    inc(i,k,n){
        while(qh<=qt&&a[q[qt]]>=a[i])qt--;
        while(qh<=qt&&q[qh]<i-k+1)qh++;
        q[++qt]=i;printf("%d ",a[q[qh]]);
    }
    printf("
");mem(q);qh=1;
    inc(i,1,k-1){
        while(qh<=qt&&a[q[qt]]<=a[i])qt--;
        q[++qt]=i;
    }
    inc(i,k,n){
        while(qh<=qt&&a[q[qt]]<=a[i])qt--;
        while(qh<=qt&&q[qh]<i-k+1)qh++;
        q[++qt]=i;printf("%d ",a[q[qh]]);
    }
    printf("
");
    return 0;
}