java - Radix Sort, the value of r -

please refer following code radix sort:

class radixsort {     public static void radix_sort_uint(int[] a, int bits)     {          int[] b = new int[a.length];         int[] b_orig = b;           int rshift = 0;         (int mask = ~(-1 << bits); mask != 0; mask <<= bits, rshift += bits) {              int[] cntarray = new int[1 << bits];              (int p = 0; p < a.length; ++p) {                 int key = (a[p] & mask) >> rshift;                 ++cntarray[key];             }           (int = 1; < cntarray.length; ++i)                         cntarray[i] += cntarray[i-1];               (int p = a.length-1; p >= 0; --p) {                 int key = (a[p] & mask) >> rshift;                 --cntarray[key];                 b[cntarray[key]] = a[p];             }               int[] temp = b; b = a; = temp;         }           if (a == b_orig)             system.arraycopy(a, 0, b, 0, a.length);     } } 

this downloaded wikipedia.

i feel algorithm work value of bits parameter divide 32 perfectly. thus, bits should 2 or 4 , not 10. please let me know if right.

short answer: no

long answer:

the probable line of confusion is:

for (int mask = ~(-1 << bits); mask != 0; mask <<= bits, rshift += bits) { 

mask <<= bits shifts bits of mask left bits, padding right zeros. if bits doesn't divide 32, full 32 bits won't utilised. while bits should divide 32, choosing value doesn't not break code.