| 18 | * @return {number[]} An array of numbers sorted in increasing order. |
| 19 | */ |
| 20 | export function bucketSort(list, size) { |
| 21 | if (undefined === size) { |
| 22 | size = 5 |
| 23 | } |
| 24 | if (list.length === 0) { |
| 25 | return list |
| 26 | } |
| 27 | let min = list[0] |
| 28 | let max = list[0] |
| 29 | // find min and max |
| 30 | for (let iList = 0; iList < list.length; iList++) { |
| 31 | if (list[iList] < min) { |
| 32 | min = list[iList] |
| 33 | } else if (list[iList] > max) { |
| 34 | max = list[iList] |
| 35 | } |
| 36 | } |
| 37 | // how many buckets we need |
| 38 | const count = Math.floor((max - min) / size) + 1 |
| 39 | |
| 40 | // create buckets |
| 41 | const buckets = [] |
| 42 | for (let iCount = 0; iCount < count; iCount++) { |
| 43 | buckets.push([]) |
| 44 | } |
| 45 | |
| 46 | // bucket fill |
| 47 | for (let iBucket = 0; iBucket < list.length; iBucket++) { |
| 48 | const key = Math.floor((list[iBucket] - min) / size) |
| 49 | buckets[key].push(list[iBucket]) |
| 50 | } |
| 51 | const sorted = [] |
| 52 | // now sort every bucket and merge it to the sorted list |
| 53 | for (let iBucket = 0; iBucket < buckets.length; iBucket++) { |
| 54 | const arr = buckets[iBucket].sort((a, b) => a - b) |
| 55 | for (let iSorted = 0; iSorted < arr.length; iSorted++) { |
| 56 | sorted.push(arr[iSorted]) |
| 57 | } |
| 58 | } |
| 59 | return sorted |
| 60 | } |