Ural Championship 2013 Problem Set

problem_a.py

# Problem A. Graphics Settings
'''
Example input:
1
vsync 10
640 480 10000000
2
Off vsync
Resolution 320 240
'''

def calculate_fps(w, h, clock, impact_factor):
    # Calculate FPS based on the following equation:
    # equation: frame_rate = clock_rate / frame_cycles / impact_factor
    # frame_cycles is gpu cycles / frame
    # clock_rate is gpy cycles / sec
    # impact_factor is unitless
    return (clock / float(w * h) / impact_factor)
    
def fps_grade(fps_list):
    # Convert list of FPS vals to ratings
    return [
        'Slideshow' if fps < 10 else
        'Perfect' if fps > 60 else
        'So-so'
        for fps in fps_list]

def data_from_lines(lines):
    # Split a range of lines into spaced components
    return [data.next().split() for _ in range(lines)]

def generator(data):
    # Parse input file and cluster data by case
    # Feed clustered data to our algorithm
    results = list()
 
    # Parse options as [option_name, impact_factor]
    number_options = data.next()
    options = {k: v for (k, v) in data_from_lines(number_options))
    
    # Generate running impact_factor
    impact_factor = sum([x[1] for x in options])
    
    # Grab the initial resolution and clock rate
    w, h, clock = [int(x) for x in data.next().split()]
    
    # Parse changes as [new_state, option_name] or [resolution, w, h]
    # note that option changes are len(change) == 2 versus resolution
    # which is len(change) == 3
    number_changes = int(data.next())
    changes = data_from_lines(number_changes)
    
    # Calculate FPS 
    # do this for initial 
    results.append(calc_fps(w, h, clock, impact_factor))
    # and then iterate through changes
    for change in changes:
        # handle a resolution change as [Resolution, w, h]
        if len(change) == 3:
            w, h = change[1:]
        # handle option change as [Off/On, Option]
        else:
            # get the impact_factor change
            perturbation = options[change[1]]
            if change[0] == 'Off':
                impact_factor -= perturbation
            else change[0] == 'On':
                impact_factor += perturbation
        results.append(calc_fps(w, h, clock, impact_factor))

    # Convert numerical FPS to categorical classifications
    return fps_grade(results)

Link to problem set as PDF: https://docs.google.com/file/d/0B2kGPJ31ig1-bXgwT1djZk1ZdjQ/edit?usp=sharing