advent-of-code/2022/python/day16.py

import sys
import matrix
import shared
import scanf
from dataclasses import dataclass
from collections import defaultdict
from typing import List, Dict
from pprint import pprint
import networkx as nx

from IPython.display import Image, display

@dataclass
class Valve:
    label: str
    rate: int
    tunnels: List[str]
    opened_at: int = -1
    potential: Dict[str, int] = None

    def set_potential(self, valves):
        self.potential = {}
        for tunnel in self.tunnels:
            self.potential[tunnel] = valves[tunnel].rate

    def highest_potential(self):
        return max(self.potential, key=self.potential.get)


def parse(rows):
    valves = {}
    for row in rows:
        left, right = row.split(" valve")
        right = right.replace("s ", "").lstrip()
        valve, rate = scanf.scanf("Valve %s has flow rate=%d; %*s %*s to", left)
        tunnels = right.split(", ")
        valves[valve] = Valve(label=valve, rate=rate, tunnels=tunnels)

    for _, v in valves.items():
        v.set_potential(valves)
    return valves


def part1(rows, sample=False):
    p1 = Part1(rows, sample, 30)
    p1.run()


class Part1:
    def __init__(self, rows, sample, minutes):
        self.rows = rows
        self.sample = sample
        self.valves = parse(rows)
        self.nonzero = {v.label: v for _, v in self.valves.items() if v.rate > 0}
        self.cur = self.valves["AA"]
        self.tick = 1
        self.minutes = minutes
        self.g = nx.DiGraph()
        self.path_distances = defaultdict(dict)
        self.set_up_graph()

    def draw(self):
        pdot = nx.drawing.nx_pydot.to_pydot(self.g)
        pdot.write_png("15.png")

    def set_up_graph(self):
        for lbl, v in self.valves.items():
            for t in v.tunnels:
                # self.g.add_edge(lbl, t, {'weight':self.valves[t].rate})
                self.g.add_edge(lbl, t, weight=self.valves[t].rate)
        all_keys = self.valves.keys()
        for lbl, _ in self.valves.items():
            for other in all_keys:
                if other == lbl:
                    continue
                self.path_distances[lbl][other] = min([len(x) for x in nx.shortest_simple_paths(self.g, lbl, other)])

    def do_tick(self, minute):
        pressure = 0
        opened = []
        for _, valve in self.valves.items():
            if valve.opened_at > 0:
                pressure += valve.rate
                opened.append(valve.label)
        print(f"== Min {minute}:: Valves {', '.join(opened)} are open, releasing {pressure} pressure")

    def calculate_total_flow(self):
        total = 0
        for label, valve in self.valves.items():
            if valve.opened_at > 0:
                total += valve.rate * (30 - valve.opened_at)
        return total

    def run(self):
        # Construct the graph with vertices & edges from the input
        # Call a function to compute the distances between every pair of vertices
        # Create a closed set containing all the valves with non-zero rates
        # At each step, iterate over the remaining set of closed, non-zero valves
        # - Subtract the distance from remaining minutes
        # - Calculate the flow (rate * remaining minutes)
        # - Remove the recently opened valve from the closed set (functionally), so the deeper levels won't consider it

        def priority(remaining):
            _pris = []
            for _,n in self.nonzero.items():
                # (time_remaining - distance_to_valve - 1) * flow rate
                pri = (remaining - self.path_distances[self.cur.label][n.label] - 1) * n.rate
                _pris.append((n.label, pri))
            _pris = list(sorted(_pris, key=lambda x: x[1], reverse=True))
            return _pris


        remaining = self.minutes 
        open_order = []
        while len(self.nonzero):
            if remaining <= 0:
                print("ran out of time")
                break
            self.do_tick(31-remaining)
            pris = priority(remaining)
            print(pris)
            _pri, _ = pris.pop(0)
            n = self.nonzero[_pri]
            del self.nonzero[_pri]
            open_order.append(n.label)
            print("\tMoving to", n.label)
            print("\tOpening ", n.label)
            distance = self.path_distances[self.cur.label][n.label]
            self.cur = n
            self.cur.opened_at = self.minutes - (remaining + 1)
            remaining -= distance # Move
            remaining -= 1 # open


        print(remaining)
        print(open_order)
        print("sample: 1651")
        print("total flow:", self.calculate_total_flow())
        


def main():
    sample = False
    if sys.argv[-1] == "--sample":
        sample = True
    rows = [row for row in shared.load_rows(16)]

    with shared.elapsed_timer() as elapsed:
        part1(rows, sample)
        print("🕒", elapsed())

    # with shared.elapsed_timer() as elapsed:
    #    part2(rows, sample)
    #    print("🕒", elapsed())


if __name__ == "__main__":
    main()