@[MA_tian](/user/909367)
```cpp
#include<bits/stdc++.h>
using namespace std;
int f[200005][20],a[200005];
int main(){
ios::sync_with_stdio(0);
// cin.tie();
// cout.tie();
cin.tie(0);
int n,m;
cin>>n>>m;
for(int i=1;i<=n;i++){
cin>>a[i];
}
for(int j=0;j<=18;j++){
for(int i=1;i+(1<<j)-1<=n;i++){
if(!j){
f[i][j]=a[i];
}else{
f[i][j]=max(f[i][j-1],f[i+(1<<j-1)][j-1]);
}
}
}
while(m--){
int c,d;
cin>>c>>d;
// int len=c-d+1,k=log(len)/log(2);
int len=d-c+1,k=log(len)/log(2);
// cout<<max(f[c][k],f[d-(1<<k)+1][k])<<endl;
cout<<max(f[c][k],f[d-(1<<k)+1][k])<<'\n';
}
return 0;
}
```
<https://www.luogu.com.cn/record/141366547>
by Argvchs @ 2023-12-30 01:14:24
@[Argvchs](/user/533270) 感谢大佬！
by MA_tian @ 2023-12-30 09:04:19