Parallel Redundancy Protocol for Railway Wireless Data Communication Network

Algorithm 3

Query operation

1. y: elements to be queried.

2. k: the number of hash functions.

3. hash: a hash function whose value range is [0, m-1], and m is the length of array B.

4. for i ←1 to k do.

5.  index ← hash(y, i);

6.  if B(index) = 0 do.

7.   return false;

8.  end if.

9. end for

10. return true