// https://programmers.co.kr/learn/courses/30/lessons/12899
function solution12909(n) {
  var answer = [];
  var arr = '';
  var N = n;

  var seq = ['4', '1', '2'];
  // console.log(seq[seq.length - 1]);
  while (true) {
    var tmp = n % 3;

    answer.push(tmp);
    // if (n <= 2) {
    //   break;
    // }

    if (tmp == 0) {
      n = (n - tmp - 3) / 3;
    } else {
      n = (n - tmp) / 3;
    }

    if (n == 0) {
      break;
    }
  }

  while (answer.length != 0) {
    arr += seq[answer.pop()];
  }

  // console.log(answer);
  // console.log(N, arr);
  // console.log("------------");
  return arr;
}

// https://programmers.co.kr/learn/courses/30/lessons/12905
//   가장 큰 정사각형 찾기
function solution(board) {
  var answer = 1;

  var lownum = board.length;
  var colnum = board[0].length;
  console.log(lownum, colnum);

  if (lownum == 1 || colnum == 1) {
    var maxRow = board.map(function (row) {
      return Math.max.apply(null, row);
    });
    var max = Math.max.apply(null, maxRow);

    return max;
  }

  var max = 0;

  for (var q = 1; q < board.length; q++) {
    for (var w = 1; w < board[0].length; w++) {
      if (board[q][w] == 0) {
        continue;
      }
      var arr = [board[q - 1][w - 1], board[q - 1][w], board[q][w - 1]];
      board[q][w] = Math.min.apply(null, arr) + 1;
      max = Math.max(max, board[q][w]);
    }
  }

  answer = max * max;

  //   console.log(maxRow, max);
  console.log(answer);
  return answer;
}

// https://programmers.co.kr/learn/courses/30/lessons/42576
const solution = (participant, completion) => {
  let objComletion = {};

  completion.forEach((item) => {
    !objComletion[item] ? (objComletion[item] = 1) : objComletion[item]++;
  });

  for (let i = 0; i < participant.length; i++)
    if (!objComletion[participant[i]] || --objComletion[participant[i]] < 0)
      return participant[i];
};
result = solution(['leo', 'kiki', 'eden'], ['eden', 'kiki']);

// https://programmers.co.kr/learn/courses/30/lessons/42840
function solution(answers) {
  const a = [1, 2, 3, 4, 5];
  const b = [2, 1, 2, 3, 2, 4, 2, 5];
  const c = [3, 3, 1, 1, 2, 2, 4, 4, 5, 5];

  let count = [0, 0, 0];
  answers.forEach((element, index) => {
    a[index % a.length] == element ? count[0]++ : null;
    b[index % b.length] == element ? count[1]++ : null;
    c[index % c.length] == element ? count[2]++ : null;
  });
  let result = [];
  let max = Math.max.apply(null, count);
  count.forEach((item, idx) => {
    if (max == item) {
      result.push(idx + 1);
    }
  });
  return result;
}
solution([1, 2, 3, 4, 5]);

// https://programmers.co.kr/learn/courses/30/lessons/42862
function solution(n, lost, reserve) {
  var answer = 0;

  let arr = [];
  for (let i = 0; i < n; i++) {
    arr[i] = 1;
  }

  for (let i = 0; i < reserve.length; i++) {
    arr[reserve[i] - 1]++;
  }

  for (let i = 0; i < lost.length; i++) {
    arr[lost[i] - 1]--;
  }

  for (let i = 0; i < arr.length; i++) {
    // 앞에사람꺼 빌리기
    if (arr[i] == 0) {
      if (arr[i - 1] == 2) {
        arr[i - 1]--;
        arr[i]++;
        continue;
      }
      // 뒤에사람꺼 빌리기
      else if (arr[i + 1] == 2) {
        arr[i + 1]--;
        arr[i]++;
        continue;
      }
    }
  }

  const result = arr.filter((value, index) => {
    return value != 0;
  });

  return result.length;
}
solution(5, [2, 4], [1, 3, 5]);

// https://programmers.co.kr/learn/courses/30/lessons/12901
// 1월:31일
// 2월:29일
// 3월:31일
// 4월:30일
// 5월:31일
// 6월:30일
// 7월:31일
// 8월:31일
// 9월:30일
// 10월:31일
// 11월:30일
// 12월:31일
function solution(a, b) {
  const days = [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
  const dow = ['SUN', 'MON', 'TUE', 'WED', 'THU', 'FRI', 'SAT'];
  let eachFirstDow = [5];
  let tmp;
  // setup process
  for (let i = 1; i < a; i++) {
    tmp = days[i - 1] % 7;
    console.log(i + 1, dow[(eachFirstDow[i - 1] + tmp) % 7]);
    eachFirstDow[i] = (eachFirstDow[i - 1] + tmp) % 7;
  }
  eachFirstDow.forEach((item) => {
    console.log(dow[item]);
  });
  tmp = (b - 1) % 7;
  return dow[(eachFirstDow[a - 1] + tmp) % 7];
}
result = solution(10, 1);
result = solution(5, 24);

// https://programmers.co.kr/learn/courses/30/lessons/12921
function solution(n) {
  var answer = 0;
  let sosu = [];
  let arr = {};
  for (let i = 2; i <= n; i++) {
    arr[i] = 1;
  }

  for (let index = 2; index <= n; index++) {
    const element = arr[index];
    if (element == 0) {
      console.log('index', index);
      continue;
    }
    sosu.push(index);
    let a = 2;
    // 지금 현재 값을
    while (true) {
      if (!(arr[index * a] + 1)) {
        break;
      }
      arr[index * a++] = 0;
      console.log(index * a);
    }
  }
  console.log('소수:', sosu);
  return sosu.length;
}
result = solution(10);

// https://programmers.co.kr/learn/courses/30/lessons/12928
function solution(n) {
  if (n == 0 || n == 1) {
    return n;

  let arr = [1, n];
  console.log(Math.sqrt(n));
  for (let index = 2; index <= Math.sqrt(n); index++) {
    if (n % index == 0) {
      arr.push(index);
      if (index == Math.sqrt(n)) {
      } else {
        arr.push(n / index);
      }
    }
  }
  console.log(arr);
  return arr.reduce((prev, curr) => {
    console.log(prev, curr);
    return curr + prev;
  }, 0);
}
result = solution(12); //28

// https://programmers.co.kr/learn/courses/30/lessons/12931
function solution(n) {
  let answer;
  n = `${n}`;
  n = n.split('');
  answer = n.reduce((prev, curr) => {
    return parseInt(curr) + parseInt(prev);
  }, 0);
  return answer;
}
result = solution(123);