RMQ

#include<iostream>
#include<cstdio>
#include<algorithm>

using namespace std;
const int N=1e6+5,LogN=20;

int log[N],f[N][LogN+5],a[N];
int n,m,x,y;

int main()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
     scanf("%d",&a[i]);
    log[0]=-1;
    //预处理边界值以及长度为1-n的log值 
    for(int i=1;i<=n;i++)
       {
           f[i][0]=a[i];
           log[i]=log[i>>1]+1;
       }
    //计算f[i][j] 
    for(int j=1;j<=LogN;j++)
       for(int i=1;i+(1<<j)-1<=n;i++) 
         f[i][j]=max(f[i][j-1],f[i+(1<<(j-1))][j-1]);
         
    scanf("%d",&m);
    while(m--)
    {
        scanf("%d%d",&x,&y);
        int s=log[y-x+1];   //求log2(y-x+1)向下取整的值 
        printf("%d\n",max(f[x][s],f[y-(1<<s)+1][s]));
    }
    
    return 0;  
}