Stars

    Lucy loves stars very much. There are N (1 <= N <= 1000) stars in the sky. Assume the sky is a flat plane. All of the stars lie on it with a location (x, y), -10000 <= x, y <= 10000. Now, Lucy wants you to tell her how many squares with each of four vertices formed by these stars, and the edges of the squares should parallel to the coordinate axes.

    The first line of input is the number of test case.
    The first line of each test case contains an integer N. The following N lines each contains two integers x, y, meaning the coordinates of the stars. All the coordinates are different.

    For each test case, output the number of squares in a single line.

2
1
1 2
4
0 0
1 0
1 1
0 1

0
1

2008 Asia Chengdu Regional Contest Online