radixSort.java

import java.util.*;

public class radixSort { 
    public static void main(String[] args) {
        int[] input = { 11, 8, 23, 5, 10, 12, 2, 14, 11, 9, 4, 4, 6, 24 }; 
        System.out.println("Before : "+Arrays.toString(input)); 
        int[] result = radixSort(input);
        System.out.println("After : "+Arrays.toString(result));    
    }

    public static int[] radixSort(int[] input) {
        final int RADIX = 10;
        List<Integer>[] bucket = new ArrayList[RADIX];
        // Do counting sort for every digit. Note that 
        // instead of passing digit number, exp is passed. 
        // exp is 10^i where i is current digit number 
        for (int i = 0; i < bucket.length; i++) {
            bucket[i] = new ArrayList<Integer>(); 
        }
        boolean maxLength = false; int tmp = -1, placement = 1;
        while (!maxLength) {
            maxLength = true;
            for (Integer i : input) {
                tmp = i / placement;
                bucket[tmp % RADIX].add(i);
                if (maxLength && tmp > 0) {
                    maxLength = false;
                }
            }

            int a = 0;
            for (int b = 0; b < RADIX; b++) {
                for (Integer i : bucket[b]) {
                    input[a++] = i;
                }
                bucket[b].clear();
            }
            placement *= RADIX;
        }
        return input;
    }
}