Write a program which reads an directed graph G=(V,E), and finds the shortest distance from vertex 1 to each vertex (the number of edges in the shortest path). Vertices are identified by IDs 1,2,...n.
In the first line, an integer n denoting the number of vertices, is given. In the next n lines, adjacent lists of vertex u are given in the following format:
u k v1 v2 ... vk
u is ID of the vertex and k denotes its degree.vi are IDs of vertices adjacent to u.
For each vertex u, print id and d in a line. id is ID of vertex u and d is the distance from vertex 1 to vertex u. If there are no path from vertex 1 to vertex u, print -1 as the shortest distance. Print in order of IDs.
4 1 2 2 4 2 1 4 3 0 4 1 3
1 0 2 1 3 2 4 1
Introduction to Algorithms, Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, and Clifford Stein. The MIT Press.