// ver2. sorterer ogs? tall mellom 2**32 og 2**31
class SekvensiellRadix{
static void radix2(int [] a) {
      // 2 digit radixSort: a[]
      int max = a[0], numBit = 2, n =a.length;
     // a) finn max verdi i a[]
      for (int i = 1 ; i < n ; i++)
           if (a[i] > max) max = a[i];
      while (max >= (1L<<numBit) )numBit++; // antall siffer i max

      // bestem antall bit i siffer1 og siffer2
        int bit1 = numBit/2,
              bit2 = numBit-bit1;
      int[] b = new int [n];
      radixSort( a,b, bit1, 0);    // f?rste siffer fra a[] til b[]
      radixSort( b,a, bit2, bit1);// andre siffer, tilbake fra b[] til a[]
 } // end


/** Sort a[] on one digit ; number of bits = maskLen, shiftet up ¡®shift¡¯ bits */
static void radixSort ( int [] a, int [] b, int maskLen, int shift){
      int  acumVal = 0, j, n = a.length;
      int mask = (1<<maskLen) -1;
      int [] count = new int [mask+1];

     // b) count=the frequency of each radix value in a
      for (int i = 0; i < n; i++) {
         count[(a[i]>> shift) & mask]++;
      }

     // c) Add up in 'count' - accumulated values
      for (int i = 0; i <= mask; i++) {
           j = count[i];
            count[i] = acumVal;
            acumVal += j;
       }
     // d) move numbers in sorted order a to b
      for (int i = 0; i < n; i++) {
         b[count[(a[i]>>shift) & mask]++] = a[i];
      }
}// end radixSort
}