88 lines
2.1 KiB
JavaScript
88 lines
2.1 KiB
JavaScript
const fs = require('fs/promises');
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const sum = (arr) => arr.reduce((total, num) => total+num, 0);
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const arrayOfLength = n => Array.from(Array(n).keys()).map(() => {});
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const createNode = (str) => {
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const stats = str.match(/Valve ([A-Z]+) has flow rate=([\d]+); tunnels? leads? to valves? (.*)$/);
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if(!stats) {
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console.log("Bad line? : ", str);
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return;
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}
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const id = stats[1];
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const rate = stats[2];
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const edges = stats[3].split(', ');
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return {
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id,
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rate,
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edges,
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};
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};
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const main = async () => {
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const input = (await fs.readFile("./input.txt", 'utf8')).split("\n").slice(0, -1).sort();
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const nodesById = {};
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for(const row of input) {
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const node = createNode(row);
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if(!node) continue;
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nodesById[node.id] = node;
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}
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const nodesByRate = Object.values(nodesById).sort((a, b) => b.rate - a.rate).filter(n => n.rate > 0);
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console.log("nodes by rate: ", nodesByRate);
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const findEachOptimalPath = (node, queue = [], visited = {}, length = 0) => {
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visited[node.id] = length;
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for(const edge of node.edges) {
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const neighbor = nodesById[edge];
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if(typeof visited[neighbor.id] === "undefined") {
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queue.push(() => findEachOptimalPath(neighbor, queue, visited, length + 1));
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}
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};
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if(queue.length) {
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return queue.shift()();
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}
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return visited;
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};
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const valvePossibilities = Object.values(nodesById).reduce((possibilities, node) => {
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possibilities[node.id] = findEachOptimalPath(node);
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return possibilities;
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}, {});
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let best = 0;
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const plan = (node, value, opened = {}, time = 30) => {
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if(node.rate > 0 && time > 0) {
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time = time - 1;
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opened[node.id] = true;
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value = value + time * node.rate;
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}
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if(value > best) {
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best = value;
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console.log(`${best} is better!`);
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}
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const distances = valvePossibilities[node.id];
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for(const next of nodesByRate.filter(n => !opened[n.id])) {
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const distance = distances[next.id];
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if(time > distance + 1) {
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plan(next, value, {...opened}, time - distances[next.id]);
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}
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}
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};
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plan(nodesById["AA"], 0);
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console.log("Answer is: ", best);
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}
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main();
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