CHASE  A Chase In WonderLand
Alice is in Wonderland. It is March and March Hare is raving mad. It begins to chase Alice. Alice runs as fast as she can, but she comes to the the edge of a quicksand pool. Now this pool has several safe spots where she may comfortably step on without being swallowed by the quicksand. She may step onto any safe spot from solid ground, but thereafter she can jump from spot to spot only in a straight line, and she cant turn back. March Hare is still hot on her heels, so she needs to know the maximum number of jumps she can make.
Input
On the first line there will be a single integer n, denoting the number of test cases. Each test case will consist of a single integer k by itself on a line, followed by k lines containing the x and y coordinates of the safe spots , seperated by a single space. Both coordinates are integer values. There are no leading or trailing spaces or blank lines. 0<k≤2200
Output
For each case print a single integer by itself on a line, with no leading or trailing spaces. Do not print blank lines.
Example
Input: 2 5 0 0 1 1 2 2 4 8 2 75 3 0 0 1 2 3 4 Output: 2 1
hide comments
uberness132:
20121112 23:32:56
TLE on O(K^2 logK) 

Gaurav Menghani:
20110612 10:59:41
A very strict time limit. Consider increasing it to 2s. 

pankaj:
20110204 14:14:39
please keep time limit to such extend that TLE should not be there because of IO. I got accepted after IO optimization. O(n^2) solution Last edit: 20110204 14:21:25 

loc_konoko:
20100804 08:44:37
I got TLE with a an O(K^2 log K) solution too T_T 

:D:
20100429 10:08:20
Miguel already solved this one, but for other people with this problem: It is possible, but you will have to use fast structures like arrays (if you know the O(K^2 log K) algo you should know what I'm reffering to). 

Miguel Oliveira:
20100215 19:36:30
I keep getting TLE with a an O(K^2 log K) solution, could anyone point me an efficient algoritm? 
Added by:  Abhilash I 
Date:  20070222 
Time limit:  1s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ERL JSRHINO NODEJS PERL6 VB.NET 
Resource:  Code Craft 2007 