Files
OI-source/1.3865.cpp
2023-08-03 09:22:52 +08:00

49 lines
718 B
C++

// luogu-judger-enable-o2
#include<cstdio>
#include<algorithm>
using namespace std;
const int maxn=1e5+10;
int n,m,l,r;
int d[maxn][20];
int a[maxn];
void RMQ_init(int *A,int n)
{
for(int i=0;i<n;i++) d[i][0]=A[i];
for(int j=1;(1<<j)<=n;j++)
for(int i=0;i+(1<<j)-1<n;i++)
d[i][j]=max(d[i][j-1],d[i+(1<<(j-1))][j-1]);
}
int RMQ(int L,int R)
{
int k=0;
while((1<<(k+1))<=R-L+1) k++;
return max(d[L][k],d[R-(1<<k)+1][k]);
}
int main()
{
#ifdef local
freopen("pro.in","r",stdin);
#endif
scanf("%d%d",&n,&m);
for(int i=0;i<n;i++) scanf("%d",&a[i]);
RMQ_init(a,n);
while(m-->0)
{
scanf("%d%d",&l,&r);
printf("%d\n",RMQ(l-1,r-1));
}
return 0;
}
/*
8 8
9 3 1 7 5 6 0 8
1 6
1 5
2 7
2 6
1 8
4 8
3 7
1 8
*/