bfs.expected

C++的一个好库。。。现在很流行

0 --> 2 
1 --> 1 3 4 
2 --> 1 3 4 
3 --> 1 4 
4 --> 0 1 
0 --> 2 
1 --> 1 3 4 
2 --> 1 3 4 
3 --> 1 4 
4 --> 0 1 
distances: 0 2 1 2 2 
parent[0] = 0
parent[1] = 2
parent[2] = 0
parent[3] = 2
parent[4] = 2