POJ1118 Lining up

Lining Up

Time Limit: 2000MS		Memory Limit: 32768K
Total Submissions: 19392		Accepted: 6133

Description

"How am I ever going to solve this problem?" said the pilot. 

Indeed, the pilot was not facing an easy task. She had to drop packages at specific points scattered in a dangerous area. Furthermore, the pilot could only fly over the area once in a straight line, and she had to fly over as many points as possible. All points were given by means of integer coordinates in a two-dimensional space. The pilot wanted to know the largest number of points from the given set that all lie on one line. Can you write a program that calculates this number? 


Your program has to be efficient! 

Input

Input consist several case,First line of the each case is an integer N ( 1 < N < 700 ),then follow N pairs of integers. Each pair of integers is separated by one blank and ended by a new-line character. The input ended by N=0.

Output

output one integer for each input case ,representing the largest number of points that all lie on one line.

Sample Input

5
1 1
2 2
3 3
9 10
10 11
0

Sample Output

3

Source

East Central North America 1994

给你几个点，求一条直线最多经过几个点。

个人纯暴力。

这题网上貌似说hash可以做，不懂啊，会的大神来给我讲讲啊

#include
#include
#include
using namespace std;
struct node
{
    double x,y;
} p[701];
bool v[701][701];
int main()
{
    int n;
    while(cin>>n)
    {
        if(n==0)return 0;
        memset(v,0,sizeof(v));
        for(int i=0; ia)a=b;
            }
        }
        cout<