73 lines
1.4 KiB
C++
73 lines
1.4 KiB
C++
#include<stdio.h>
|
|
#include<iostream>
|
|
#include<string.h>
|
|
#include<math.h>
|
|
#include<algorithm>
|
|
using namespace std;
|
|
const int MAXN=100010;
|
|
int a[MAXN];
|
|
int b[MAXN];
|
|
int dp[MAXN][20];
|
|
void makeRMQ(int n,int b[])
|
|
{
|
|
for(int i=0;i<n;i++)
|
|
dp[i][0]=b[i];
|
|
for(int j=1;(1<<j)<=n;j++)
|
|
for(int i=0;i+(1<<j)-1<n;i++)
|
|
dp[i][j]=max(dp[i][j-1],dp[i+(1<<(j-1))][j-1]);
|
|
}
|
|
int rmq(int s,int v)
|
|
{
|
|
int k=(int)(log(v-s+1.0)/log(2.0));
|
|
return max(dp[s][k],dp[v-(1<<k)+1][k]);
|
|
}
|
|
int bi_search(int s,int t)
|
|
{
|
|
int tmp=a[t];
|
|
int l=s;
|
|
int r=t;
|
|
int mid;
|
|
while(l<r)
|
|
{
|
|
mid=((l+r)>>1);
|
|
if(a[mid]>=tmp)r=mid;
|
|
else l=mid+1;
|
|
}
|
|
return r;
|
|
}
|
|
int main()
|
|
{
|
|
int n,q;
|
|
int s,t;
|
|
while(scanf("%d",&n),n)
|
|
{
|
|
scanf("%d",&q);
|
|
for(int i=0;i<n;i++)
|
|
scanf("%d",&a[i]);
|
|
int tmp;
|
|
for(int i=n-1;i>=0;i--)
|
|
{
|
|
if(i==n-1)tmp=1;
|
|
else
|
|
{
|
|
if(a[i]==a[i+1])tmp++;
|
|
else tmp=1;
|
|
}
|
|
b[i]=tmp;
|
|
}
|
|
makeRMQ(n,b);
|
|
while(q--)
|
|
{
|
|
scanf("%d%d",&s,&t);
|
|
s--;
|
|
t--;
|
|
int temp=bi_search(s,t);
|
|
int ans=t-temp+1;
|
|
t=temp-1;
|
|
if(s>t)printf("%d\n",ans);
|
|
else printf("%d\n",max(ans,rmq(s,t)));
|
|
}
|
|
}
|
|
return 0;
|
|
}
|