📚 문제

https://programmers.co.kr/learn/courses/30/lessons/72411

💡 접근

⌨️ 코드

function solution(orders, course) {
    let listObj = {};
    let answer = [];

  function combination(arr, n) {
    let result = [];

    if (n === 1) return arr.map((v) => [v]);
    arr.forEach((fixed, idx, origin) => {
      let rest = origin.slice(idx + 1);
      let combinationArr = combination(rest, n - 1);
      let attached = combinationArr.map((c) => [fixed, ...c]);
      result.push(...attached);
    });
    return result;
  }

  orders.map((o) => {
    const orderArr = o.split("").sort();

    for (let i = 0; i < course.length; i++) {
      const orderCombis = combination(orderArr, course[i]);
      orderCombis.map(orderCombi => {
          const string = orderCombi.join("");
            if (listObj[string]) listObj[string] += 1;
            else listObj[string] = 1;
      });
    }
  });

  const listArr = Object.entries(listObj);
  course.map(c => {
      const candidates = listArr.filter(l => l[0].length == c && l[1] > 1);
      if (candidates.length > 0){
          let max = Math.max(... candidates.map(v => v[1]));
          candidates.forEach(v => {
              if (v[1] == max) answer.push(v[0]);
          })
      }    
  })
  return answer.sort();
}

📝 리뷰