@Test
public void testRadixSort() {

    int a = 1;
    int b = 87654321;
    int c = 2147483647;
    System.out.println("number: " + a + ", bit: " + SortUtil.getDigitBit(a));
    System.out.println("number: " + b + ", bit: " + SortUtil.getDigitBit(b));
    System.out.println("number: " + c + ", bit: " + SortUtil.getDigitBit(c));
    System.out.println("number: " + c + ", 1 bit is: " + SortUtil.getFigure(c, 1) + ", 5 bit is: " + SortUtil.getFigure(c, 5) + ", 10 bit is: " + SortUtil.getFigure(c, 10));
    int[] testArray = {10000, 4, 12, 0, 456, 789, 88, 66, 1224, 1204, 1412, 12345};
    int maxBit = 1;
    for (int i = 0; i < testArray.length; i++) {
        int numberBit = SortUtil.getDigitBit(testArray[i]);
        if (numberBit > maxBit) {
            maxBit = numberBit;
        }
    }
    SortUtil.radixSort(testArray, maxBit);
    System.out.println("call radixSort, result is: ");
    for (int i = 0; i < testArray.length; i++) {
        System.out.println(testArray[i] + "\t");
    }
    System.out.println();
}