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bin_sort.go
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/
bin_sort.go
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package main
import (
"fmt"
"math/rand"
"sort"
)
// Bucket is a type alias of []float32. It is used in BucketSort() to represent
// individual buckets.
type Bucket []float32
// Methods required for sort.Sort()
func (b Bucket) Len() int {
return len(b)
}
func (b Bucket) Swap(i, j int) {
b[i], b[j] = b[j], b[i]
}
func (b Bucket) Less(i, j int) bool {
return b[i] < b[j]
}
// BucketSort sorts provided slice of floats using Bucket Sort algorithm
// Time Complexity: O(n)-> Avg case and O(n^2)-> Worst Case
// Constraints: 0 <= arr[i] <= 1
func BucketSort(arr []float32) []float32 {
n := len(arr)
// Create n empty buckets, each can hold up to n elements
buckets := make([]Bucket, n)
for i := 0; i < n; i++ {
// Set length to 0, but allocate memory for n elements
buckets[i] = make([]float32, 0, n)
}
// Place all the elements into corresponding buckets
for i := 0; i < n; i++ {
bi := int(float32(n) * arr[i])
buckets[bi] = append(buckets[bi], arr[i])
}
// Sort elements in each bucket
for i := 0; i < n; i++ {
sort.Sort(buckets[i])
}
// Put sorted elements into the resulting array
sorted := make([]float32, 0, n)
for i := 0; i < n; i++ {
for j := 0; j < len(buckets[i]); j++ {
sorted = append(sorted, buckets[i][j])
}
}
return sorted
}
func makeRandomNumbers(n int) []float32 {
arr := make([]float32, n)
for i := range arr {
arr[i] = rand.Float32()
}
return arr
}
func main() {
n := 10
arr := makeRandomNumbers(n)
sorted := BucketSort(arr)
fmt.Println(sorted)
}