programming-examples/java/Searching_Sorting_Algorithms/Java Program to Implement Radix Sort.java

/**
 ** Java Program to Implement Radix Sort
 **/

import java.util.Scanner;

/** Class RadixSort **/
public class RadixSort
{
    /** Radix Sort function **/
    public static void sort( int[] a)
    {
        int i, m = a[0], exp = 1, n = a.length;
        int[] b = new int[10];
        for (i = 1; i < n; i++)
            if (a[i] > m)
                m = a[i];
        while (m / exp > 0)
            {
                int[] bucket = new int[10];
                for (i = 0; i < n; i++)
                    bucket[(a[i] / exp) % 10]++;
                for (i = 1; i < 10; i++)
                    bucket[i] += bucket[i - 1];
                for (i = n - 1; i >= 0; i--)
                    b[--bucket[(a[i] / exp) % 10]] = a[i];
                for (i = 0; i < n; i++)
                    a[i] = b[i];
                exp *= 10;
            }
    }
    /** Main method **/
    public static void main(String[] args)
    {
        Scanner scan = new Scanner( System.in );
        System.out.println("Radix Sort Test\n");
        int n, i;
        /** Accept number of elements **/
        System.out.println("Enter number of integer elements");
        n = scan.nextInt();
        /** Create integer array on n elements **/
        int arr[] = new int[ n ];
        /** Accept elements **/
        System.out.println("\nEnter "+ n +" integer elements");
        for (i = 0; i < n; i++)
            arr[i] = scan.nextInt();
        /** Call method sort **/
        sort(arr);
        /** Print sorted Array **/
        System.out.println("\nElements after sorting ");
        for (i = 0; i < n; i++)
            System.out.print(arr[i]+" ");
        System.out.println();
    }
}

/*Enter number of integer elements
10

Enter 10 integer elements
877 567 3456 876 467 26 934 9876 1 4567

Elements after sorting
1 26 467 567 876 877 934 3456 4567 9876*/