Problem Description

A square is a 4-sided polygon whose sides have equal length and adjacent sides form 90-degree angles. It is also a polygon such that rotating about its centre by 90 degrees gives the same polygon. It is not the only polygon with the latter property, however, as a regular octagon also has this property. 

So we all know what a square looks like, but can we find all possible squares that can be formed from a set of stars in a night sky? To make the problem easier, we will assume that the night sky is a 2-dimensional plane, and each star is specified by its x and y coordinates. 

 

 

Input

The input consists of a number of test cases. Each test case starts with the integer n (1 <= n <= 1000) indicating the number of points to follow. Each of the next n lines specify the x and y coordinates (two integers) of each point. You may assume that the points are distinct and the magnitudes of the coordinates are less than 20000. The input is terminated when n = 0.

 

 

Output

For each test case, print on a line the number of squares one can form from the given stars.

 

 

Sample Input

4 1 0 0 1 1 1 0 0 9 0 0 1 0 2 0 0 2 1 2 2 2 0 1 1 1 2 1 4 -2 5 3 7 0 0 5 2 0

 

 

Sample Output

1 6 1

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记着标记数组要用boolean类型

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1 #include
       
         2 #include
        
          3 #include
         
           4 #include
          
            5 #include
           
             6 #include
            
              7 using namespace std; 8 int x[1010],y[1010]; 9 bool fs[5000][5000];//此处要定义成bool类型的，否则超内存10 int a,b,c,i,j,sum,n;11 int f(int a,int b)12 {13 if(fs[a+2500][b+2500])14 return 1;15 return 0;16 }17 18 int main()19 {20 int x1,y1,x2,y2,x3,y3,x4,y4;21 int a,b,i,j,sum,n;22 while(scanf("%d",&n)&&n)23 {24 sum=0;25 memset(fs,0,sizeof(fs));26 for(i=0;i