fast sort failed with "int[] a = new int[]{30,34,3,1,67,5,12};"

[Chunliang Lin]

When test with “int[] a = new int[]{30,34,3,1,67,5,12};", fast sort will end with result: 1, 3, 5, 12, 30, 67, 34; And the code for swap() did not swap but replace the old value.