关于st表

 #include<cstdio>
 #include<iostream>
 #include<cmath>
 #include<cctype>
 #include<algorithm>
 using namespace std;
 int n,m;
 int logg[];
 int maxx[][];
 inline int read(){
     int ret=;
     char ch=getchar();
     while(ch<''||ch>'')ch=getchar();
     while(ch>=''&&ch<='')ret=ret*+ch-'',ch=getchar();
     return ret;
 }
 int main(){
     n=read(),m=read();
     logg[]=-;
     for(int i=;i<=n;++i)maxx[i][]=read(),logg[i]=logg[i>>]+;
     for(int i=;i<=;++i){
         for(int j=;j+(<<i)-<=n;++j){
             maxx[j][i]=max(maxx[j][i-],maxx[j+(<<i-)][i-]);
         }
     }
     for(int i=;i<=m;++i){
         int l,r;
         l=read();r=read();int len=logg[r-l+];
         cout<<max(maxx[l][len],maxx[r-(<<len)+][len]);putchar('\n');
     }
     return ;
 }

代码