DWITE Online Computer Programming Contest

November 2009

Problem 1

Angles

Angles are a vital part of game physics, and are relevant to velocities, collisions, and other interactions between objects. As such, it's important to be able to accurately calculate angles between points.

The input file **DATA1.txt** will contain 5 lines, each containing two points. **x1 y1 x2 y2**. All values are integer values -100 <= n <= 100. The angle should be calculated between the first point, the origin at (0,0), and the second point, in a *clockwise direction*.

The output file **OUT1.txt** will contain 5 lines, each a corresponding angle between the points through the origin, rounded to the nearest 1/10th of a degree. If the angle is a whole degree, output the trailing .0

Sample Input (first 4 shown):

71 71 100 0 100 0 71 71 0 100 0 -100 -100 0 0 -100

Sample Output (first 4 shown):

45.0 315.0 180.0 270.0