uva 10534 Wavio Sequence LIS 栈实现nlogn

#include<stdio.h>
#include<string.h>
#define maxn 10010
int st[maxn],z[maxn],f[maxn],a[maxn],n,top;
int min(int a,int b)
{
return a>b?b:a;
}
int max(int a,int b)
{
return a>b?a:b;
}
int main()
{
int i,j,k,l;
while(~scanf("%d",&n))
{
memset(st,0,sizeof(st));
memset(f,0,sizeof(f));
memset(z,0,sizeof(z));
for(i=0;i<n;i++)
{
scanf("%d",&a[i]);
}
top=1;
st[1]=a[0];
z[0]=1;
for(i=1;i<n;i++)
{
if(a[i]>st[top])
{
top++;
st[top]=a[i];
z[i]=top;
}
else
{
int l,r,m;
l=1;r=top;
while(l<=r)
{
m=(l+r)>>1;
//if(st[m]==a[i])
//break;
if(st[m]<a[i])
{
l=m+1;
}
else
r=m-1;
}
z[i]=l;
st[l]=a[i];
}
}
memset(st,0,sizeof(st));
top=1;
f[n-1]=1;
st[top]=a[n-1];
for(i=n-2;i>=0;i--)
{
if(a[i]>st[top])
{
top++;
st[top]=a[i];
f[i]=top;
}
else
{
int l,r,m;
l=1;r=top;
while(l<=r)
{
m=(l+r)>>1;
if(st[m]<a[i])
{
l=m+1;
}
else
r=m-1;
}
f[i]=l;
st[l]=a[i];
printf("l%d r%d m%d\n",l,r,m);
}
}
int end=-1;
for(i=0;i<n;i++)
{
int t=min(z[i],f[i]);
end=max(t,end);
}
printf("%d\n",end*2-1);
}
return 0;
}