Algorithm 1 Deriving the permutation with initial node
Input: all nodes' neighborhood N; the initial node A.
Output: node location permutation S.
1.	S (1) = A; i = 2;
2.	while Ns (i−1) is not empty do
3.	S (i) = the first element of Ns (i−1)
4.	delete S (i − 1) in the N
5.	i = i + 1
6.	end while
7.	output the location permutation S