56 lines
1.3 KiB
JavaScript
56 lines
1.3 KiB
JavaScript
|
import { readFileSync } from 'node:fs';
|
||
|
|
||
|
const input = readFileSync('input', 'utf-8');
|
||
|
|
||
|
const cycles = input
|
||
|
.split('\n')
|
||
|
.filter(line => line)
|
||
|
.flatMap((() => {
|
||
|
let x = 1;
|
||
|
return (line) => {
|
||
|
if (line.startsWith('noop')) {
|
||
|
return [x];
|
||
|
}
|
||
|
if (line.startsWith('addx')) {
|
||
|
const add = parseInt(line.substring(5));
|
||
|
if (isNaN(add)) {
|
||
|
throw new Error('Invalid value for addx');
|
||
|
}
|
||
|
const result = [x, x];
|
||
|
x += add;
|
||
|
return result;
|
||
|
}
|
||
|
};
|
||
|
})());
|
||
|
|
||
|
const sumOfSignalStrengths = [20, 60, 100, 140, 180, 220]
|
||
|
.map(c => {
|
||
|
const x = cycles[c - 1];
|
||
|
const strength = c * x;
|
||
|
return strength;
|
||
|
})
|
||
|
.reduce((total, strength) => total + strength);
|
||
|
|
||
|
console.log(
|
||
|
`The sum of observed signal strengths is: ${sumOfSignalStrengths}`
|
||
|
);
|
||
|
|
||
|
const render = cycles
|
||
|
.map((x, c) => {
|
||
|
const scanPos = c % 40;
|
||
|
return [x - 1, x, x + 1].some(pixelPos => pixelPos === scanPos);
|
||
|
})
|
||
|
.reduce((display, pixelVisible, c) => {
|
||
|
const scanLine = Math.floor(c / 40);
|
||
|
if (!display[scanLine]) {
|
||
|
display.push([]);
|
||
|
}
|
||
|
display[scanLine].push(pixelVisible ? '#' : ' ');
|
||
|
return display;
|
||
|
}, [])
|
||
|
.map(scanLine => scanLine.join(''))
|
||
|
.join('\n');
|
||
|
|
||
|
console.log('Display output:');
|
||
|
console.log(render);
|