hdu 1025 Constructing Roads In JGShining's Kingdom 最长上升序列nlogn

#include<bits/stdc++.h>using namespace std;int d[500000+5],a[500000+5];int Binary_search(int s,int t,int i){    int mid;    while(s<t)    {        mid=(s+t)>>1;        if(i>=d[mid]) s=mid+1;        else t=mid;    }    return s;}int main(){    int i,n,b,p,r,k,cas=0;    while(~scanf("%d",&n))    {        for(i=0; i<n; i++)        {            scanf("%d%d",&p,&r);            a[p]=r;        }        b=1;        memset(d,0,sizeof(d));        d[0]=a[1];        for(i=2; i<=n; i++)        {            k=Binary_search(0,b-1,a[i]);            if(d[k]>=a[i]) d[k]=a[i];            else d[b++]=a[i];        }        printf("Case %d:\n",++cas);        if(b==1) printf("My king, at most 1 road can be built.\n\n");        else printf("My king, at most %d roads can be built.\n\n",b);    }    return 0;}