arrowsort.py

import time

from collections import defaultdict


class Entity:
    def __init__(self, value):
        self.value = value
        self.pos = 0
        self.vel = value

    def move(self):
        self.pos += self.vel
        if self.pos <= 0:
            return self.value
        self.vel -= 1


def print_entities(edct):
    print("\n" * 100)
    for i in range(max(edct.keys()))[::-1]:
        try:
            print(edct[i][0].value)
        except IndexError:
            print("-")
    time.sleep(1)


def arrowsort(lst, output=None):
    rlst = []
    edct = defaultdict(list, {0: list(map(Entity, lst))})
    while True:
        if output:
            output(edct)
        new_edct = defaultdict(list)
        for n in edct:
            for x in edct[n]:
                r = x.move()
                if r is not None:
                    rlst.append(r)
                else:
                    new_edct[x.pos].append(x)
        if not new_edct:
            return rlst
        edct = new_edct


if __name__ == "__main__":
    print(arrowsort(eval(input()), print_entities))