public static int[] invertPermutation(int... input){
        int[] target = new int[input.length];

        for(int i = 0 ; i < input.length ; i++){
            target[input[i]] = i;
        }

        return target;
    }
@Test
    public void testInvertPermutationLong(){
        assertArrayEquals(
                new long[]{ 2, 4, 3, 0, 1 },
                ArrayUtil.invertPermutation(3L, 4L, 0L, 2L, 1L)
        );
    }