47 lines
1.1 KiB
JavaScript
47 lines
1.1 KiB
JavaScript
const { Glib } = require('../../lib');
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const START = 0b0;
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const END = 0b1111111111;
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const decode = (bp) => {
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if (!bp.match(/^[bf]+[lr]+$/i, '')) {
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throw new Error('invalid input');
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}
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const binary = bp.replace(/[br]/gi, '1').replace(/[fl]/gi, '0');
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return BigInt('0b' + binary);
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};
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const encode = (seatId, columnCharacters, length) => {
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const binary = seatId.toString(2).padStart(length, '0');
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return (
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binary
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.slice(0, -columnCharacters)
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.replace(/1/g, 'B')
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.replace(/0/g, 'F') +
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binary
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.slice(-columnCharacters)
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.replace(/1/g, 'R')
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.replace(/0/g, 'L')
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);
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};
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module.exports = {
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'1': (input) =>
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Glib.fromLines(input)
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.map(decode)
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.reduce((max, current) => (max > current ? max : current), -Infinity),
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'2': (input) => {
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const foundSid = new Map(
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Glib.fromLines(input).map((bp) => [decode(bp), bp]),
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);
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return Glib.fromSequence(START, END)
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.filter(
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(sid) =>
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!foundSid.has(sid) &&
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foundSid.has(sid - 1n) &&
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foundSid.has(sid + 1n),
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)
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.join();
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},
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};
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