76 lines
1.9 KiB
TypeScript
76 lines
1.9 KiB
TypeScript
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import fs from "node:fs";
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import { printTime, now } from "../util";
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type tile = { guard: boolean; blocked: boolean; visited: boolean };
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const test = true;
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const data = fs.readFileSync(
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test ? "./inputs/testinput" : "./inputs/input",
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"utf8"
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);
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let timer = now.instant();
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console.log(
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"part one:",
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(() => {
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let floor = data
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.split("\n")
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.slice(0, -1)
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.reduce((floor, row, i) => {
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row.split("").forEach((v, col) => {
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floor[`${i}|${col}`] = {
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guard: v === "^",
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blocked: v === "#",
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visited: false,
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};
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});
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return floor;
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}, {} as Record<string, tile>);
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let direction = "north";
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let [guard] = Object.entries(floor).filter((tile) => tile[1].guard)[0];
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while (true) {
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let [x, y] = guard.split("|").map((v) => parseInt(v, 10));
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floor[guard].visited = true;
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let next = "";
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switch (direction) {
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case "north":
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next = `${x - 1}|${y}`;
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break;
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case "south":
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next = `${x + 1}|${y}`;
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break;
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case "east":
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next = `${x}|${y + 1}`;
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break;
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case "west":
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next = `${x}|${y - 1}`;
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break;
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}
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if (floor[next] === undefined) {
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break;
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}
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if (!floor[next].blocked) {
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floor[next].guard = true;
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floor[guard].guard = false;
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guard = next;
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} else {
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if (direction === "north") {
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direction = "east";
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} else if (direction === "east") {
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direction = "south";
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} else if (direction === "south") {
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direction = "west";
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} else if (direction === "west") {
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direction = "north";
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}
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}
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}
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return Object.entries(floor).reduce((total, tile) => {
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return total + (tile[1].visited ? 1 : 0);
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}, 0);
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})(),
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printTime(now.instant().since(timer))
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);
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