Vertex representation of a weighted unidirectional graph
I am using adjacency matrix to represent all the vertex of my weighted unidirectional large graph. In this graph no edge connects a vertex to itself. This makes all the diagonal elements of my adjacency matrix `null`. As my graph is large so in adjacency matrix i need not to save any elements in left triangle. Below is a small sample graph with adjacency matrix. ![This is the sample small graph with adjacency matrix][1] 


  [1]: http://i.stack.imgur.com/mSPY6.png

In an unidirectional graph left triangle is just mirror image of right triangle. i.e. `adjacency_matrix[i][j]`, `adjacency_matrix[j][i]` are same. so why to store the left triangle. for a large graph this trick can save so much memory. At the same time diagonal elements are also zero since no edge connects a vertex to itself. i.e. `adjacency_matrix[i][i]` are zero.
But how can i implement this? can 2D array be used here?
Vertex representation of a weighted unidirectional graph
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I am using adjacency matrix to represent all the vertex of my weighted unidirectional large graph. In this graph no edge connects a vertex to itself. This makes all the diagonal elements of my adjacency matrix `null`. As my graph is large so in adjacency matrix i need not to save any elements in left triangle. Below is a small sample graph with adjacency matrix. ![This is the sample small graph with adjacency matrix][1] 


  [1]: http://i.stack.imgur.com/mSPY6.png

In an unidirectional graph left triangle is just mirror image of right triangle. i.e. `adjacency_matrix[i][j]`, `adjacency_matrix[j][i]` are same. so why to store the left triangle. for a large graph this trick can save so much memory. At the same time diagonal elements are also zero since no edge connects a vertex to itself. i.e. `adjacency_matrix[i][i]` are zero.
But how can i implement this? can 2D array be used here?