pkg.py

"""
OO Design: design data types for Amazon locker and packages
Requirement: Design an optimized algorithm to fit the package in the right locker
"""
import bisect
class Locker:
    def __init__(self, x, y , z, **kwargs):
        self.length = x
        self.width = y
        self.height = z
        self.locker_id = kwargs.get('id', None)
        self.vacant = True

    def get_max_dimension(self):
        return max([self.length, self.width, self.height])

class Package:
    def __init__(self, x, y, z, **kwargs):
        self.length = x
        self.width = y
        self.height = z
        self.package_id = kwargs.get('id', None)


class LockerLocator:
    def __init__ (self, lockers = None):
        self.lockers = lockers
        self.sorted_lockers = sorted((x.get_max_dimension(), x) for x in self.lockers)

    def find_locker_for_box(self, box):
        # given a box, find a suitable unoccupied locker
        # lockers in the locator is sorted by max dimension 
        # first fit the box's maximum dimension, then try to rotate the box
        # and find the first fit for the remaining two dimensions
        maxd = max([box.length, box.width, box.height])
        index = bisect.bisect_left(self.sorted_lockers, maxd)
        for i in range(index, len(self.sorted_lockers)):
            if not self.sorted_lockers[i][1].vacant:
                continue
            if self.check_fit(self.sorted_lockers[i][1], box):
                self.sorted_lockers[i][1].vacant = False
                return self.sorted_lockers[i][1].id
    
    def check_fit(self, locker, box):
        """
        sort the three dimensions, and check each dimension of the box fits
        into the locker
        """
        locker_dimensions = sorted([locker.length, locker.width, locker.height])
        box_dimensions = sorted([box.length, box.width, box.height])
        for i in range(3):
            if box_dimensions[i] <=locker_dimensions[i]:
                return True
        return False