championshipPoints.js (8kyu 76)

in about Dev on Algorithm

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Problem

  • Write a function that takes such list and counts the points of our team in the championship.
    • 챔피언십에서 우리 팀의 점수를 계산한다.


Rules:

if x > y: 3 points

if x < y: 0 point

if x = y: 1 point

There are 10 matches in the championship

0 <= x <= 4

0 <= y <= 4


Solution 01

function championshipPoints(games) {
  let result = 0;
  
  for (let i = 0; i < games.length; i++) {
    if (games[i][0] > games[i][2]) result += 3;
    if (games[i][0] === games[i][2]) result += 1;
  }
  return result;
}

championshipPoints(['1:0', '2:0', '3:0', '4:0', '2:1', '3:1', '4:1', '3:2', '4:2', '4:3']);  // 30
championshipPoints(['1:1', '2:2', '3:3', '4:4', '2:2', '3:3', '4:4', '3:3', '4:4', '4:4']);  // 10


Solution 02

function championshipPoints(games) {
  let result = 0;
  
  games.map(i => {
    i[0] > i[2] ? result += 3 : i[0] === i[2] ? result += 1 : result += 0;
  });
  return result;
}

championshipPoints(['1:0', '2:0', '3:0', '4:0', '2:1', '3:1', '4:1', '3:2', '4:2', '4:3']);  // 30
championshipPoints(['1:1', '2:2', '3:3', '4:4', '2:2', '3:3', '4:4', '3:3', '4:4', '4:4']);  // 10

map() 메소드

배열 내 모든 element에 대해, 호출한 함수의 결과를 모아 새 배열로 반환한다.


Solution 03

function championshipPoints(games) {
  let result = 0;
  
  games.forEach(i => {
    i[0] > i[2] ? result += 3 : i[0] === i[2] ? result += 1 : result += 0;
  });
  return result;
}

championshipPoints(['1:0', '2:0', '3:0', '4:0', '2:1', '3:1', '4:1', '3:2', '4:2', '4:3']);  // 30
championshipPoints(['1:1', '2:2', '3:3', '4:4', '2:2', '3:3', '4:4', '3:3', '4:4', '4:4']);  // 10

forEach() 메소드

배열의 각 element에 대해, 제공된 함수를 차례로 한 번씩 호출한다.


Solution 04

function championshipPoints(games) {
  return games.reduce((result, i) => {
    return result += i[0] > i[2] ? 3 : i[0] === i[2] ? 1 : 0;
  }, 0);
}

championshipPoints(['1:0', '2:0', '3:0', '4:0', '2:1', '3:1', '4:1', '3:2', '4:2', '4:3']);  // 30
championshipPoints(['1:1', '2:2', '3:3', '4:4', '2:2', '3:3', '4:4', '3:3', '4:4', '4:4']);  // 10

reduce() 메소드

배열을 하나의 값으로 줄이고, 그 값을 반환한다.