Adjacency matrix Direction diagram (ii) C + + detailed

An introduction to the graph of adjacency matrix

The direction graph of adjacency matrix refers to a direction graph expressed by adjacency matrix.

The above figure G2 contains a total of 7 vertices of "a,b,c,d,e,f,g" and contains "<A,B>,<B,C>,<B,E>,<B,F>,<C,E>,<D,C>" <E,B>,<E,D>,<F,G> "A total of 9 sides.

The matrix on the right of the above figure is a schematic diagram of the adjacency matrix in memory of the G2. A[i][j]=1 means that the first vertex to the J Vertex is an edge, a[i][j]=0 represents not an edge, while A[i][j] represents the value of column J of Line I, for example, a[1,2]=1, which means that the 1th vertex (i.e. vertex b) to 2nd vertex (C) is an edge.

Code description of the direction graph of adjacency matrix

1. Basic definition

#define MAX
    
class Matrixdg {
    private:
        char Mvexs[max];    Vertex set
        int mvexnum;             Vertex number
        int medgnum;             Number of edges
        int Mmatrix[max][max];   Adjacency Matrix public
    
    :
        //create diagram (own input data)
        MATRIXDG ();
        Create diagram (with provided matrix)
        MATRIXDG (char vexs[], int vlen, char edges[][2], int elen);
        ~MATRIXDG ();
    
        Print matrix queue diagram
        void print ();
    
    Private:
        //Read an input character
        char Readchar ();
        Returns the position of the CH in the Mmatrix matrix
        int getPosition (char ch);

MATRIXDG is a structural body corresponding to the graph of adjacency matrix.

Mvexs is used to save vertices, Mvexnum is the number of vertices, medgnum is the number of edges, and Mmatrix is a two-dimensional array for storing matrix information. For example, mmatrix[i][j]=1, which means "vertex I (i.e. mvexs[i])" and "Vertex J (i.e. Mvexs[j])" are adjacency points, and vertex i is the starting point, and Vertex J is the endpoint.

2. Create a matrix

This provides two ways to create matrices. One is with known data , and the other requires the user to enter data manually .

2.1 Creating the diagram (with the provided matrix)

* *
 Create diagram (with provided matrix) *
 parameter description:
 *     vexs  -vertex array
 *     Vlen-  vertex array length
 *     edges --Edge Array
 *     Elen  --Length of Edge
 array
/MATRIXDG::MATRIXDG (char vexs[], int vlen, char edges[][2], int Elen )
{
    int i, p1, p2;
    
    Initialize "vertex number" and "number of edges"
    mvexnum = Vlen;
    Medgnum = Elen;
    Initialize "vertex" for
    (i = 0; i < mvexnum i++)
        mvexs[i] = vexs[i];
    
    Initializes the "side"
    for (i = 0; i < medgnum; i++)
    {
        //Read the start vertex and end vertex of the edge
        p1 = getPosition (edges[i][0));
        P2 = getPosition (edges[i][1]);
    
        MMATRIX[P1][P2] = 1;
    }
}

The function is to create an adjacency matrix with a direction graph. In fact, the method creates a direction graph, which is the figure G2 above. Its invocation method is as follows:

Char vexs[] = {' A ', ' B ', ' C ', ' D ', ' E ', ' F ', ' G '};
Char edges[][2] = {
    {' A ', ' B '}, 
    {' B ', ' C '}, {' B ', ' 
    e '}, 
    {' B ', ' F '}, 
    {' C ', ' e '}, 
    {' D ', ' C '}, 
    {' E ', ' B '}, 
    {' E ', ' D '}, 
    {' F ', ' G '}}; 
int vlen = sizeof (VEXS)/sizeof (vexs[0));
int elen = sizeof (edges)/sizeof (edges[0));
matrixdg* PG;
    
PG = new MATRIXDG (Vexs, Vlen, edges, Elen);