function solution(s) { return [...s].sort().reverse().join(''); }

function solution(s) { if (!s) return true; let cntOfP = 0; let cntOfY = 0; [...s.toUpperCase()].forEach(word => { word === 'P' ? ++cntOfP : word === 'Y' ? ++cntOfY : null; }); return cntOfP === cntOfY ? true : false; }

function solution(strings, n) { return strings.sort((a, b) => (a[n] === b[n] ? a.localeCompare(b) : a[n].localeCompare(b[n]))); }

function solution(a, b) { if (a === b) return a; const startNum = a < b ? a : b; const endNum = a < b ? b : a; let result = 0; for (let i = startNum; i

function solution(arr, divisor) { const result = arr.filter(e => e % divisor === 0); return result.length ? result.sort((a, b) => a - b) : [-1]; }

function solution(arr) { return arr.filter((_, i) => arr[i] !== arr[i - 1]); }

function solution(s) { return s.length % 2 ? s.substr(s.length / 2, 1) : s.substr(s.length / 2 - 1, 2); }

function solution(array, commands) { return commands.map( ([start, end, select]) => array .slice(start - 1, end) .sort((a, b) => a - b)[select - 1] ); }

function solution(a, b) { const day = ['SUN', 'MON', 'TUE', 'WED', 'THU', 'FRI', 'SAT']; return day[new Date(`2016/${a}/${b}`).getDay()]; } // ----- 다른 방법 ----- function solution(a, b) { const month = [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]; const week = ['THU', 'FRI', 'SAT', 'SUN', 'MON', 'TUE', 'WED']; let day = b; for (let i = 0; i < a - 1; i++) day += month[i]; return week[day % 7]; }

function solution(n, lost, reserve) { const students = Array(n).fill(1); const afterStudents = students.map((amount, i) => { if (lost.includes(i + 1)) --amount; if (reserve.includes(i + 1)) ++amount; return amount; }); afterStudents.forEach((amount, i, arr) => { if (amount === 0 && i !== arr.length - 1 && arr[i + 1] === 2) { arr[i] += 1; arr[i + 1] -= 1; } else if (amount === 0 && i !== 0 && arr..