【luogu P1440】求(DQ)M区间内的最小值

[code]#include<iostream>
using namespace std;
const int MAXN = 2e6 + 5;
struct dot
{
    int x,z;
    dot(){x = 0;z = 0;}
}q[MAXN];
int s=1,t=0;//队列，头指针，尾指针 
void push(int x,int z)
{
    while(q[t].x > x && t >= s)
        t --;
    t ++;
    q[t].x = x;
    q[t].z = z; 
    return;
}
void pop()
{
    s ++;
}
dot front()
{
    return q[s];
}
int n,k,z,ans;
int main()
{
    scanf("%d %d",&n,&k);
    cout << front().x << endl;
    for(int i = 1;i < n;i ++)
    {
        scanf("%d",&z);
        push(z,i + k);
        dot x = front();
        while(x.z <= i)
        {
            pop();
            x = front();
        }
        printf("%d\n",x.x);
    }
    return 0;
}