LeetCode: Relative Ranks Solution

Approach: Sorting and Hash Table

(commented in implementation)

Implementation

1var findRelativeRanks = function (score) {
2  const [aBeforeB, bBeforeA] = [-1, 1] // for better readability when do sorting below
3
4  const positionRankMap = {
5    0: "Gold Medal",
6    1: "Silver Medal",
7    2: "Bronze Medal",
8  }
9
10  const indexRankMap = Object.fromEntries(
11    score
12      .map((s, i) => [s, i]) // create array of [score, index]
13      .sort(([sA], [sB]) => (sA > sB ? aBeforeB : bBeforeA)) // sort the array by score, descending
14      .map(([_, originalScoreIndex], index) => [
15        positionRankMap[index] || String(index + 1),
16        originalScoreIndex,
17      ]) // create array of [rank name, index in original score]
18      .map(([rank, originalScoreIndex]) => [originalScoreIndex, rank]) // to convert to object in the next step
19  )
20
21  return score.map((_, i) => indexRankMap[i])
22}