Compile

g++ main.cpp -DK={s in the paper = K * 32} -DD={d in the paper} -O3 -std=c++11 -o bfl

Run

./bfl {graph} {query}

Graph File  Format
The first line must be "graph_for_greach".

The second line  contains V, the number of vertices of the graph.

Then V lines follow.
Each line describes edges from a certain vertex, u, to its successors, v_i, in the following format.
u: v_1 v_2 ... v_deg+(u)#

Query File Format
Each line contains a query, Reach(u, v), in the following format.
u v result
If result is 0, then Reach(u, v) should be false;
if result is 1, then Reach(u, v) should be true;
otherwise result should be -1, which means the result it unknown.

Please note vertices are numbered from 0 to V - 1, and the graph must be a DAG.