6464: 洛谷P1142 - Lining Up
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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!
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
The input begins with a single positive integer on a line by itself indicating the number of the cases
following, each of them as described below.
This line is followed by a blank line, and there is also a blank line between two consecutive inputs. The input consists of $N$ pairs of integers, where $1 < N < 700$.
Each pair of integers is separated by one blank and ended by a new-line character. The list of pairs is ended with an end-of-file character. No pair will occur twice.
This line is followed by a blank line, and there is also a blank line between two consecutive inputs. The input consists of $N$ pairs of integers, where $1 < N < 700$.
Each pair of integers is separated by one blank and ended by a new-line character. The list of pairs is ended with an end-of-file character. No pair will occur twice.
Output
For each test case, the output must follow the description below.
The outputs of two consecutive cases will be separated by a blank line. The output consists of one integer representing the largest number of points that all lie on one line.
The outputs of two consecutive cases will be separated by a blank line. The output consists of one integer representing the largest number of points that all lie on one line.
Sample 1 Input
5
1 1
2 2
3 3
9 10
10 11
Sample 1 Output
3