Creating an adjacency Matrix from a JUNG Graph.

Question

Graph < Integer, Integer> g = new SparseMultigraph<Integer, Integer>();
    g.addVertex(1);g.addVertex(2);g.addVertex(3);
    g.addEdge(0,1,2 ,EdgeType.DIRECTED);g.addEdge(1,2,3 ,EdgeType.DIRECTED);g.addEdge(2,3,1 ,EdgeType.DIRECTED);g.addEdge(3,1,3 ,EdgeType.DIRECTED);

How can I convert this graph into an adjacency matrix taking into consideration that it is a directed graph.

Answer 1

In this post you can find an adjacency matrix:

Breadth and depth first search - part 3

How to implement it?

// Adjacency matrix
int map[21][21] = {

/*   A B C D E F G H I L M N O P R S T U V Z */
  {0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0},
  {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,1}, // Arad
  {2,0,0,0,0,0,1,1,0,0,0,0,0,0,1,0,0,0,1,0,0}, // Bucharest
  {3,0,0,0,1,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0}, // Craiova
  {4,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0}, // Dobreta
  {5,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0}, // Eforie
  {6,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0}, // Fagaras
  {7,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}, // Girgiu
  {8,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0}, // Hirsova
  {9,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,1,0}, // Iasi
  {0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0}, // Lugoj
  {1,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0}, // Mehadia
  {2,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0}, // Neamt
  {3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,1}, // Oradea
  {4,0,1,1,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0}, // Pitesti
  {5,0,0,1,0,0,0,0,0,0,0,0,0,0,1,0,1,0,0,0,0}, // Rimnicu Vilcea
  {6,1,0,0,0,0,1,0,0,0,0,0,0,1,0,1,0,0,0,0,0}, // Sibiu
  {7,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0}, // Timisoara
  {8,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,1,0}, // Urziceni
  {9,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,0,0}, // Vaslui
  {0,1,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0}  // Zerind
};

Note that the first commented line represents the initial letter of each city's name. The mapping done with the adjacency matrix refers to these letters so that it's easier to understand. For example, getting the first entry of the adjacency matrix that refers to Arad: we have that Arad has paths that lead us to Sibiu, Timisoara and Zerind, thus we put a value of 1 on the columns that represent those cities, in this case, the columns beneath the letters S, T and Z. That's how the mapping is done. We put a value of 0 on the other columns to state that there is no path that leads us to those cities.

Given your graph, iterate its edges and create your adjacency matrix.