OJ-Problems-Source/HDOJ/4251_autoAC.cpp
2016-09-04 15:25:29 +08:00

83 lines
1.8 KiB
C++

#include<iostream>
#include<algorithm>
using namespace std;
const int N=100010;
int srted[N];
struct node
{
int num[N];
int val[N];
}t[40];
int n,m;
void build(int l,int r,int d)
{
if(l==r) return;
int mid=(l+r)>>1;
int midd=srted[mid];
int same=mid-l+1,samed=0,zn=l-1,yn=mid,i;
for(i=l;i<=r;++i)
if(t[d].val[i]<midd) --same;
for(i=l;i<=r;++i)
{
if(i==l) t[d].num[i]=0;
else t[d].num[i]=t[d].num[i-1];
if(t[d].val[i]<midd)
{
++t[d].num[i];
t[d+1].val[++zn]=t[d].val[i];
}else if(t[d].val[i]>midd)
{
t[d+1].val[++yn]=t[d].val[i];
}else
{
if(samed<same)
{
++samed;
++t[d].num[i];
t[d+1].val[++zn]=t[d].val[i];
}else
t[d+1].val[++yn]=t[d].val[i];
}
}
build(l,mid,d+1);
build(mid+1,r,d+1);
}
int query(int a,int b,int k,int l,int r,int d)
{
if(a==b) return t[d].val[a];
int mid=(l+r)>>1;
int sx=t[d].num[a-1],sy=t[d].num[b];
if(a-1<l) sx=0;
if(sy-sx>=k)
return query(l+sx,l+sy-1,k,l,mid,d+1);
else
{
int s1=(a==1?0:a-l-sx);
int s2=(b-a+1)-(sy-sx);
int nk=k-(sy-sx);
return query(mid+1+s1,mid+s1+s2,nk,mid+1,r,d+1);
}
}
int main()
{
int cas=1;
int i,a,b;
while(cin>>n)
{
cout<<"Case "<<cas++<<":"<<endl;
for(i=1;i<=n;++i)
{
cin>>srted[i];
t[0].val[i]=srted[i];
}
sort(srted+1,srted+1+n);
build(1,n,0);
cin>>m;
for(i=1;i<=m;++i)
{
cin>>a>>b;
cout<<query(a,b,(a+b)/2-a+1,1,n,0)<<endl;
}
}
}