70分TLE求调

#include <bits/stdc++.h>
using namespace std;
#define int long long
inline int read()
{
	int x=0,f=1;char ch=getchar();
	while (ch<'0'||ch>'9'){if (ch=='-') f=-1;ch=getchar();}
	while (ch>='0'&&ch<='9'){x=x*10+ch-48;ch=getchar();}
	return x*f;
}
int n,m;
int f[100005][55];
signed main()
{
    ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	n=read();m=read();
	for(int i=1;i<=n;i++) f[i][0]=read();
	for(int i=1;i<=log2(n);i++)
	{
		for(int j=1;j<=n-(1<<i)+1;j++)
		{
			f[j][i]=max(f[j][i-1],f[j+(1<<(i-1))][i-1]);
		}
	}
	for(int i=1;i<=m;i++)
	{
		int l=read(),r=read();
		int p=log2(r-l+1);
		cout<<max(f[l][p],f[r-(1<<p)+1][p])<<endl;
	}
	return 0;
}