aoc-2023/day_18/solve_2.ts
2024-12-09 22:41:02 +09:00

79 lines
2.3 KiB
TypeScript

import { transformEdgeLine, Direction, Instruction, readInput, calcArea } from "./solver.ts";
async function NewReadInput(filename: string): Promise<Instruction[]> {
const input = await Deno.readTextFile(filename);
const lines = input.split("\n").map(x => x.trim()).filter(x => x.length > 0);
return lines.map(line => {
const m = /^([RDLU])\s+(\d+)\s+\(#([0-9a-f]+)\)$/.exec(line);
if (!m) {
throw new Error(`unknown line ${line}`);
}
const steps = parseInt(m[3].slice(0,5), 16);
const direction = {
[0]: "R",
[1]: "D",
[2]: "L",
[3]: "U",
}[parseInt(m[3].slice(5,6))];
return {
direction: direction as Direction,
steps,
color: parseInt(m[3], 16),
}
});
}
const input = await NewReadInput("example.txt");
// console.log(input)
function calcWidthAndHeight(insts: Instruction[]){
let maxX = 0, maxY = 0;
let minX = 0, minY = 0;
insts.reduce<[number,number]>(([x,y]: [number, number], b: Instruction) => {
maxX = Math.max(maxX, x);
maxY = Math.max(maxY, y);
minX = Math.min(minX, x);
minY = Math.min(minY, y);
if (b.direction === "R"){
return [x + b.steps, y];
}
if (b.direction === "L"){
return [x - b.steps, y];
}
if (b.direction === "U"){
return [x, y - b.steps];
}
if (b.direction === "D"){
return [x, y + b.steps];
}
throw new Error(`unknown direction ${b.direction}`);
}, [0,0] as [number, number]);
return {
size: [maxX - minX + 1, maxY - minY + 1],
initPos: [-minX, -minY]
};
}
const {size:[width, height],
initPos: [initX, initY]} = calcWidthAndHeight(input);
console.log((`x: ${width}, y: ${height}`));
let pos = [initX, initY];
transformEdgeLine(input).forEach(inst => {
if (inst.direction === "R"){
pos = [pos[0] + inst.steps, pos[1]];
}
if (inst.direction === "L"){
pos = [pos[0] - inst.steps, pos[1]];
}
if (inst.direction === "U"){
pos = [pos[0], pos[1] - inst.steps];
}
if (inst.direction === "D"){
pos = [pos[0], pos[1] + inst.steps];
}
// console.log(`(${pos[0]}, ${pos[1]})`, inst);
});
console.log(calcArea(input));