import * as fs from "fs"; function load(filename) { let data = fs.readFileSync(filename, "utf8").trim(); const l = data.length; let i = 0; return { next: function () { const c = data[i]; i = (i + 1) % l; return c; } }; } const shapes = [ [0b0011110], [0b0001000, 0b0011100, 0b0001000], [0b0000100, 0b0000100, 0b0011100], [0b0010000, 0b0010000, 0b0010000, 0b0010000], [0b0011000, 0b0011000], ]; const shapes_len = shapes.length; class Shape { constructor(shape) { this.shape = shape; this.length = shape.length; } fall(field) { // returns true if the shape fell without colliding for (let i=0; i<this.length; ++i) { const next = field.get(i+1); if (next === undefined || next & this.shape[i]) { //collision field.solidify(this.shape); return false; } } field.fall(); return true; } shift(field, direction) { let collision = false; let tmp; switch(direction) { case ">": tmp = this.shape.map(line => { if (line & 0b1) { // we touch the right edge already collision = true; } return line >>> 1; }); break; case "<": tmp = this.shape.map(line => { if (line & 0b1000000) { // we touch the left edge already collision = true; } return line << 1; }); break; default: throw "invalid direction character in shape shift: " + direction; } if (collision) { return; } for (let i=0; i<this.length; ++i) { if (field.get(i) & tmp[i]) { //collision return; } } this.shape = tmp; } print() { this.shape.forEach(line => { console.log( line & 0b1000000 ? "#" : ".", line & 0b0100000 ? "#" : ".", line & 0b0010000 ? "#" : ".", line & 0b0001000 ? "#" : ".", line & 0b0000100 ? "#" : ".", line & 0b0000010 ? "#" : ".", line & 0b0000001 ? "#" : ".", ); }); console.log("======="); } } class Shaper { constructor() { this.index = 0; } next(field) { const s = new Shape(shapes[this.index]); field.accomodate(shapes[this.index].length + 3); this.index = (this.index + 1) % shapes_len; return s; } } class Field { constructor() { this.data = []; this.offset = 0; } accomodate(n) { this.offset = 0; for(let i=0; i<n; ++i) { this.data.unshift(0); } } fall() { if (this.data[0] !== 0) { // we need to fall bellow the top line? this.offset++; } else { this.data.shift(); } } get(offset) { return this.data[this.offset + offset]; } print() { this.data.forEach(line => { console.log( line & 0b1000000 ? "#" : ".", line & 0b0100000 ? "#" : ".", line & 0b0010000 ? "#" : ".", line & 0b0001000 ? "#" : ".", line & 0b0000100 ? "#" : ".", line & 0b0000010 ? "#" : ".", line & 0b0000001 ? "#" : ".", ); }); console.log("-------"); } solidify(shape) { for(let i=0; i<shape.length; ++i) { this.data[i+this.offset] |= shape[i]; } } } let example = load("example"); let input = load("input"); function solve(input) { let field = new Field(); let shaper = new Shaper(); for(let i=0; i<2022; ++i) { let shape = shaper.next(field); do { shape.shift(field, input.next()); } while(shape.fall(field)); } field.print(); return field.data.length; } const exampleOutput = solve(example); if (exampleOutput !== 3068) { console.log("Example failed with height " + exampleOutput); process.exit(1); // eslint-disable-line } console.log(solve(input));