const fs = require('fs'); const data = fs.readFileSync('input.txt', 'utf-8'); const lines = data.split('\n'); let max = 0 // who really needs semicolons anyway for (let i = 0; i < lines.length; i++) { let line = lines[i] let rowCode = line.substring(0, 7).replace(/F/g, "0").replace(/B/g, "1") let colCode = line.substring(7).replace(/L/g, "0").replace(/R/g, "1") // another excuse to flex that recursive muscle function getIndexFromBSP (BSP, min, max) { if (BSP.length != 1) { [min, max] = getIndexFromBSP (BSP.substring(0, BSP.length-1), min, max) } switch (BSP[BSP.length-1]) { case '0': max = Math.floor((min + max) / 2) break case '1': min = Math.ceil((min + max) / 2) break default: console.log("something went wrong") } return [min, max] } let row = getIndexFromBSP(rowCode, 0, 127)[0] let col = getIndexFromBSP(colCode, 0, 7)[0] let seatID = (row * 8) + col max = seatID > max ? seatID : max } console.log(max)