radixsort.java

   private static int getMax(int arr[]) {
       int max = arr[0];
       for (int num : arr) {
           if (num > max) max = num;
       }
       return max;
   }


   private static void sort(int[] a) {

       int i, maxOne, exp = 1, size = a.length;

       int[] listOfNumbers = new int[10];

       maxOne = getMax(a);

       while (maxOne / exp > 0) {

           int[] bucket = new int[10];

           for (i = 0; i < size; i++) {
               int number = a[i];
               int digit = (number / exp) % 10;
               bucket[digit]++;
           }

           for (i = 1; i < 10; i++)
               bucket[i] += bucket[i - 1];


           for (i = size - 1; i >= 0; i--) {      //This part of the code is problem
               int number = a[i];
               int digit = (number / exp) % 10;
               bucket[digit] -= 1;
               listOfNumbers[bucket[digit]] = a[i];
           }

           for (i = 0; i < size; i++)
               a[i] = listOfNumbers[i];

           exp *= 10;
       }
   }