/** * Concat arrays in one. * * @param arrays Arrays. * @return Summary array. */ public static int[] concat(int[]... arrays) { assert arrays != null; assert arrays.length > 1; int len = 0; for (int[] a : arrays) len += a.length; int[] r = Arrays.copyOf(arrays[0], len); for (int i = 1, shift = 0; i < arrays.length; i++) { shift += arrays[i - 1].length; System.arraycopy(arrays[i], 0, r, shift, arrays[i].length); } return r; }