poj1065

#include <iostream>
#include <algorithm>
using namespace std;
struct point {
 int x,y;
}p[5005];
int a[5005];
bool cmp(point a,point b)
{
 if(a.x==b.x) return a.y>b.y;
 return a.x>b.x;
} 
int main(int argc, char *argv[])
{
 int t,n,m,i,j,*k;
  cin>>t;
  while(t--)
  {
   cin>>n;m=1;
   for(i=0;i<n;i++)
   cin>>p[i].x>>p[i].y;
   sort(p,p+n,cmp);
   a[0]=p[0].y;
  for(i=1;i<n;i++)
  if(p[i].y>a[m-1]) a[m++]=p[i].y;
  else {
   k=lower_bound(a,a+m,p[i].y);
   a[k-a]=p[i].y;
  } 
  cout<<m<<endl;
  }
 return 0;
}//求有幾個遞減序列，就是求最長單調遞增的長度