Implementation of Bucket Sort Algorithm

Below is the implementation for the Bucket Sort:

C++
#include <iostream>
#include <vector>
using namespace std;

// Insertion sort function to sort individual buckets
void insertionSort(vector<float>& bucket) {
    for (int i = 1; i < bucket.size(); ++i) {
        float key = bucket[i];
        int j = i - 1;
        while (j >= 0 && bucket[j] > key) {
            bucket[j + 1] = bucket[j];
            j--;
        }
        bucket[j + 1] = key;
    }
}

// Function to sort arr[] of size n using bucket sort
void bucketSort(float arr[], int n) {
    // 1) Create n empty buckets
    vector<float> b[n];

    // 2) Put array elements in different buckets
    for (int i = 0; i < n; i++) {
        int bi = n * arr[i];
        b[bi].push_back(arr[i]);
    }

    // 3) Sort individual buckets using insertion sort
    for (int i = 0; i < n; i++) {
        insertionSort(b[i]);
    }

    // 4) Concatenate all buckets into arr[]
    int index = 0;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < b[i].size(); j++) {
            arr[index++] = b[i][j];
        }
    }
}

// Driver program to test above function
int main() {
    float arr[] = {0.897, 0.565, 0.656, 0.1234, 0.665, 0.3434};
    int n = sizeof(arr) / sizeof(arr[0]);
    bucketSort(arr, n);

    cout << "Sorted array is \n";
    for (int i = 0; i < n; i++) {
        cout << arr[i] << " ";
    }
    return 0;
}
Java
import java.util.ArrayList;
import java.util.List;

public class Main {
    // Insertion sort function to sort individual buckets
    public static void insertionSort(List<Float> bucket) {
        for (int i = 1; i < bucket.size(); ++i) {
            float key = bucket.get(i);
            int j = i - 1;
            while (j >= 0 && bucket.get(j) > key) {
                bucket.set(j + 1, bucket.get(j));
                j--;
            }
            bucket.set(j + 1, key);
        }
    }

    // Function to sort arr[] of size n using bucket sort
    public static void bucketSort(float[] arr) {
        int n = arr.length;

        // 1) Create n empty buckets
        List<Float>[] buckets = new ArrayList[n];
        for (int i = 0; i < n; i++) {
            buckets[i] = new ArrayList<>();
        }

        // 2) Put array elements in different buckets
        for (int i = 0; i < n; i++) {
            int bi = (int) (n * arr[i]);
            buckets[bi].add(arr[i]);
        }

        // 3) Sort individual buckets using insertion sort
        for (int i = 0; i < n; i++) {
            insertionSort(buckets[i]);
        }

        // 4) Concatenate all buckets into arr[]
        int index = 0;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < buckets[i].size(); j++) {
                arr[index++] = buckets[i].get(j);
            }
        }
    }

    // Driver program to test above function
    public static void main(String[] args) {
        float[] arr = {0.897f, 0.565f, 0.656f, 0.1234f, 0.665f, 0.3434f};
        bucketSort(arr);

        System.out.println("Sorted array is:");
        for (float num : arr) {
            System.out.print(num + " ");
        }
    }
}
Python
def insertion_sort(bucket):
    for i in range(1, len(bucket)):
        key = bucket[i]
        j = i - 1
        while j >= 0 and bucket[j] > key:
            bucket[j + 1] = bucket[j]
            j -= 1
        bucket[j + 1] = key

def bucket_sort(arr):
    n = len(arr)
    buckets = [[] for _ in range(n)]

    # Put array elements in different buckets
    for num in arr:
        bi = int(n * num)
        buckets[bi].append(num)

    # Sort individual buckets using insertion sort
    for bucket in buckets:
        insertion_sort(bucket)

    # Concatenate all buckets into arr[]
    index = 0
    for bucket in buckets:
        for num in bucket:
            arr[index] = num
            index += 1

arr = [0.897, 0.565, 0.656, 0.1234, 0.665, 0.3434]
bucket_sort(arr)
print("Sorted array is:")
print(" ".join(map(str, arr)))
C#
using System;
using System.Collections.Generic;

class Program
{
    // Insertion sort function to sort individual buckets
    static void InsertionSort(List<float> bucket)
    {
        for (int i = 1; i < bucket.Count; ++i)
        {
            float key = bucket[i];
            int j = i - 1;
            while (j >= 0 && bucket[j] > key)
            {
                bucket[j + 1] = bucket[j];
                j--;
            }
            bucket[j + 1] = key;
        }
    }

    // Function to sort arr[] of size n using bucket sort
    static void BucketSort(float[] arr)
    {
        int n = arr.Length;

        // 1) Create n empty buckets
        List<float>[] buckets = new List<float>[n];
        for (int i = 0; i < n; i++)
        {
            buckets[i] = new List<float>();
        }

        // 2) Put array elements in different buckets
        for (int i = 0; i < n; i++)
        {
            int bi = (int)(n * arr[i]);
            buckets[bi].Add(arr[i]);
        }

        // 3) Sort individual buckets using insertion sort
        for (int i = 0; i < n; i++)
        {
            InsertionSort(buckets[i]);
        }

        // 4) Concatenate all buckets into arr[]
        int index = 0;
        for (int i = 0; i < n; i++)
        {
            for (int j = 0; j < buckets[i].Count; j++)
            {
                arr[index++] = buckets[i][j];
            }
        }
    }

    // Driver program to test above function
    static void Main(string[] args)
    {
        float[] arr = { 0.897f, 0.565f, 0.656f, 0.1234f, 0.665f, 0.3434f };
        BucketSort(arr);

        Console.WriteLine("Sorted array is:");
        foreach (float num in arr)
        {
            Console.Write(num + " ");
        }
    }
}
JavaScript
function insertionSort(bucket) {
    for (let i = 1; i < bucket.length; ++i) {
        let key = bucket[i];
        let j = i - 1;
        while (j >= 0 && bucket[j] > key) {
            bucket[j + 1] = bucket[j];
            j--;
        }
        bucket[j + 1] = key;
    }
}

function bucketSort(arr) {
    let n = arr.length;
    let buckets = Array.from({length: n}, () => []);

    // Put array elements in different buckets
    for (let i = 0; i < n; i++) {
        let bi = Math.floor(n * arr[i]);
        buckets[bi].push(arr[i]);
    }

    // Sort individual buckets using insertion sort
    for (let i = 0; i < n; i++) {
        insertionSort(buckets[i]);
    }

    // Concatenate all buckets into arr[]
    let index = 0;
    for (let i = 0; i < n; i++) {
        for (let j = 0; j < buckets[i].length; j++) {
            arr[index++] = buckets[i][j];
        }
    }
}

let arr = [0.897, 0.565, 0.656, 0.1234, 0.665, 0.3434];
bucketSort(arr);
console.log("Sorted array is:");
console.log(arr.join(" "));

Output
Sorted array is 
0.1234 0.3434 0.565 0.656 0.665 0.897 

Bucket Sort – Data Structures and Algorithms Tutorials

Bucket sort is a sorting technique that involves dividing elements into various groups, or buckets. These buckets are formed by uniformly distributing the elements. Once the elements are divided into buckets, they can be sorted using any other sorting algorithm. Finally, the sorted elements are gathered together in an ordered fashion.

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