AdventOfCode/2017/24/solution.py

#!/bin/python3
import sys,re
from pprint import pprint
sys.path.insert(0, '../../')
from fred import list2int,get_re,nprint,lprint

input_f = 'input'

part = 2
#########################################
#                                       #
#              Part 1                   #
#                                       #
#########################################

def parse_input(input_f):
    list_of_components = []
    with open(input_f) as file:
        for line in file:
            l = get_re(r"^(\d+)\/(\d+)$",line.rstrip())
            list_of_components.append([int(l.group(1)),int(l.group(2))])
    return list_of_components

def make_bridge(components, last):
    score = 0
    longest_bridge = []
    for cdx, component in enumerate(components):
        if component[0] == last or component[1] == last:
            if component[0] == last:
                tmp = component[1]
            else:
                tmp = component[0]
            x = component + make_bridge(components[:cdx]+components[cdx+1:],tmp)
            if sum(x) > score:
                score = sum(x)
                longest_bridge = x
    return longest_bridge

if part == 1:
    components = parse_input(input_f)

    bridge = make_bridge(components,0)
    print(bridge)


#########################################
#                                       #
#              Part 2                   #
#                                       #
#########################################

def make_bridge_longest(components, last):
    score = 0
    longest_bridge = []
    for cdx, component in enumerate(components):
        if component[0] == last or component[1] == last:
            if component[0] == last:
                tmp = component[1]
            else:
                tmp = component[0]
            x = component + make_bridge_longest(components[:cdx]+components[cdx+1:],tmp)
            if len(x) >= len(longest_bridge):
                longest_bridge = x
                
    return longest_bridge


if part == 2:
    components = parse_input(input_f)
    bridge = make_bridge_longest(components,0)
    print(sum(bridge))