• 10

## Learning Opportunities

This puzzle can be solved using the following concepts. Practice using these concepts and improve your skills.

## Goal

Given a point X in an orthonormal coordinate system, you must find the number of triangles formed by the other given points in which X is inside.
`Example 1INPUT  REPRESENTATION  OUTPUT  COMMENTX 2;3  B(1;5)          1       X is inside the triangle ABC3      |\A 1;1  | \B 1;5  |  \C 5;1  | x(2;3)       |    \       |_____\       A(1;1) C(5;1)Example 2INPUT  REPRESENTATION  OUTPUT  COMMENTX 2;3  B(1;5)  D(5;5)  2       X is inside the triangles ABC and ABD        _____4      |\    /|A 1;1  | \  / |B 1;5  |  \/  |C 5;1  | x(2;3)D 5;5  | /  \ |       |/____\|       A(1;1) C(5;1)`
Input
Line 1: X x;y string for the coordinates of point X. x and y are floats.
Line 2: an integer n for the number of points to read.
Next n Lines p x;y for the points with their coordinates used to build triangles, x and y are floats.
Output
c Number of triangles where X is inside.
Constraints
The triangles ABC, CBA, BCA... are considered as the same triangle.
All points are unique: they have different names and coordinates.
n <= 100
Example
Input
```X 2;3
3
A 1;1
B 1;5
C 5;1```
Output
`1`

A higher resolution is required to access the IDE