#!/usr/bin/env python3

import sys
from copy import deepcopy


def compress(mem):
    blocks = deepcopy(mem)
    r = len(blocks) - 1
    for p, b in enumerate(blocks):
        if b == None:
            while blocks[r] == None: r -= 1
            # if you check this before moving it obviously does not work
            if p >= r: break
            blocks[p] = blocks[r]
            blocks[r] = None
    return blocks


def block_compress(free, full, size):
    memory = [None] * size
    for id, pos in reversed(full.items()):
        p, b = pos
        for i in sorted(free.keys()):
            if i >= p: break
            if free[i] < b: continue
            else: p = i
        if p != pos[0]:
            free[p+b] = free[p] - b
            free.pop(p)
            if (pos[0]+b) in free:
                free[pos[0]] = b + free[pos[0]+b]
                free.pop(pos[0]+b)
            else: free[pos[0]] = b
        for j in range (p, p+b): memory[j] = id
    return memory


def checksum(blocks):
    cs = 0
    for p, b in enumerate(blocks):
        if b == None: continue
        cs += p * b
    return cs


if __name__ == '__main__':
    blocks = [int(n) for n in list(open(sys.argv[1]).read().strip('\n'))]

    memory = [None] * sum(blocks)
    p, id = 0, 0
    free, full = {}, {}

    for i, b in enumerate(blocks):
        if i % 2 == 0 and b > 0:
            for j in range (p, p+b): memory[j] = id
            full[id] = (p, b)
            id += 1
        else: free[p] = b
        p += b

    # challenge 1
    res1 = checksum(compress(memory))
    print(f"challenge 1:\n{res1}\n")

    # challenge 2
    res2 = checksum(block_compress(free, full, sum(blocks)))
    print(f"challenge 2:\n{res2}")