advent-of-code/2022/16-proboscidea-volcanium/first.js
2022-12-27 11:18:43 +01:00

76 lines
1.7 KiB
JavaScript

import * as fs from "fs";
import { PriorityQueue } from "./priority_queue.js";
const regexp = /Valve ([A-Z]+) has flow rate=(\d+); tunnels? leads? to valves? ([A-Z, ]+)/;
let valves = {};
let uv = []; // useful valves
fs.readFileSync("input", "utf8")
.trim()
.split("\n")
.map(line => {
let a = line.match(regexp);
valves[a[1]] = {
cost: undefined,
label: a[1],
links: a[3].split(", "),
rate: a[2],
computePathCostTo: function (target) {
Object.values(valves).forEach(v => v.cost = 0);
let nq = new PriorityQueue();
nq.enqueue(this, 0);
while (true) {
let n = nq.dequeue();
if (n.element.label === target) {
return n.element.cost + 1; // +1 to account for opening the valve
}
n.element.links.forEach(l => {
let v = valves[l];
if (v.cost === 0) {
v.cost = n.element.cost + 1;
nq.enqueue(v, v.cost);
}
});
}
},
};
if (a[2] > 0) {
uv.push(a[1]);
}
});
let paths = {};
uv.forEach(v => {
paths["AA"+v] = valves["AA"].computePathCostTo(v);
uv.forEach(w => {
if (v !== w) {
paths[v+w] = valves[v].computePathCostTo(w);
paths[w+v] = paths[v+w];
}
});
});
let max = 0;
let parcours = [{current: "AA", actives: uv, timeLeft: 30, pressure: 0}];
for(let i=0; i<parcours.length; i++) {
let p = parcours[i];
p.pressure += valves[p.current].rate * p.timeLeft;
if (max < p.pressure) {
max = p.pressure;
}
p.actives.forEach(v => {
const cost = paths[p.current+v];
if (p.timeLeft - cost > 0) {
parcours.push({
current:v,
actives:p.actives.filter(f => f !== v), // this creates a shallow copy
timeLeft: p.timeLeft - cost,
pressure: p.pressure,
});
}
});
}
console.log(max);