HDU 1025 最长上升子序列

#include<iostream>
using namespace std;
#define N 500001
int dp
;
int a
;
int main(void)
{
int n,k=1;
while(~scanf("%d",&n))
{
int i;
for(i=0;i<n;i++)
{
int x,y;
scanf("%d%d",&x,&y);
a[x]=y;
}
memset(dp,0,sizeof(dp));
int ans=1;
dp[1]=a[1];
for(i=2;i<=n;i++)
{
int f=1,l=ans;
while(f<=l)
{
int mid=(f+l)>>1;
if(a[i]<=dp[mid])
l=mid-1;
else
f=mid+1;
}
dp[f]=a[i];
if(f>ans)
ans++;
}
printf("Case %d:/nMy king, at most %d road",k++,ans);
if(ans!=1) printf("s");
printf(" can be built./n/n");
}
}