显示代码纯文本
#include <cstdio>
#include <cstring>
using namespace std;
int data[50000],datar[50000],n,ans[50000],ansr[50000],len,lenr;
int MIN(int a,int b)
{return a>b? b:a;}
int bs(int dt)
{
int l=1,r=len,m;
while(l<r)
{
m=l+(r-l)/2;
if(ans[m]>dt) r=m;
else l=m+1;
}
return l;
}
int bsr(int dt)
{
int l=1,r=lenr,m;
while(l<r)
{
m=l+(r-l)/2;
if(ansr[m]>dt) r=m;
else l=m+1;
}
return l;
}
int main()
{
freopen("egroup.in","r",stdin);
freopen("egroup.out","w",stdout);
scanf("%d",&n);
for(int i=1;i<=n;i++)
{scanf("%d",&data[i]);datar[n-i+1]=data[i];}
ans[1]=data[1];len=1;
for(int i=2;i<=n;i++)
{
if(ans[len]<=data[i])
ans[++len]=data[i];
else
ans[bs(data[i])]=data[i];
}
ansr[1]=datar[1];lenr=1;
for(int i=2;i<=n;i++)
{
if(ansr[lenr]<=datar[i])
ansr[++lenr]=datar[i];
else
ansr[bsr(datar[i])]=datar[i];
}
printf("%d",MIN(n-len,n-lenr));
return 0;
}