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#include "graph.h"
/* Thdse functions can use for both direct or undirect graph,
* only be affected by argument 'directed' we give
*/
void retreat(char * str)
{
fprintf(stderr,"%s\n",str);
exit(EXIT_FAILURE);
}
void initializeGraph(graph * g, bool directed)
{
int i; /* counter */
g->nvertices = 0;
g->nedges = 0;
g->directed = directed;
for (i = 1; i <= MAXV; i++)
g->degree[i] = 0;
for (i = 1; i <= MAXV; i++)
g->edges[i] = NULL;
}
/* x, y is a pair of vertices */
void insertEdge(graph * g, int x, int y, bool directed)
{
edgeNode * p; /* temporary pointer */
p = (edgeNode *) malloc (sizeof(edgeNode));
if (!p)
retreat("Error allocate memory p");
p->weight = 0;
p->y = y;
p->next = g->edges[x]; /* insert at head */
g->edges[x] = p;
g->degree[x]++;
if (!directed)
insertEdge(g,y,x,true); /* add another one for undirected */
else
g->nedges++;
}
void readGraph(graph * g, bool directed)
{
int i; /* counter */
int m; /* number of edges */
int x, y; /* vertices in edge (x, y) / <x, y> */
printf("Enter number of vertices and edges: ");
scanf ("%d%d", &(g->nvertices), &m); /* read number of vertices and edges */
printf("Enter two vertices consist one edge: ");
for (i = 1; i <= m; i++)
{
scanf("%d %d", &x, &y); /* readindex and vertex */
insertEdge(g,x,y,directed); /* this is the one to make a graph */
}
}
void printGraph(graph * g)
{
int i; /* counter */
edgeNode * p; /* temporary pointer */
for (i = 1; i <= g->nvertices; i++)
{
printf("%d: ",i);
p = g->edges[i];
while (p)
{
printf(" %d", p->y);
p = p->next;
}
putchar('\n');
}
}
void purgeGraph(graph * g)
{
int i; /* counter */
edgeNode * p, * q; /* temporary pointer */
for (i = 1; i < g->nvertices; i++)
{
p = g->edges[i];
while (p)
{
q = p;
p = p->next;
free(q);
}
}
}
void initializeSearch(graph * g)
{
int i;
// time = 0;
for (i = 0; i <= g->nvertices; i++)
{
g->processed[i] = false;
g->discovered[i] = false;
g->parent[i] = -1;
}
}
void processVertexEarly(int v)
{
printf("processed vertex %d\n",v);
}
void processVertexLate(int v)
{
}
void processEdge(int v, int y)
{
printf("Process edge (%d,%d)\n",v,y);
}
void bfs(graph * g, int start)
{
queue q; /* queue of vertices to visit */
int v; /* current vertex */
int y; /* successor vertex */
edgeNode * p; /* temporary pointer */
initializeSearch(g);
initQueue(&q);
enQueue(&q,start);
g->discovered[start] = true;
while (!emptyQueue(&q))
{
v = deQueue(&q);
processVertexEarly(v);
g->processed[v] = true;
p = g->edges[v];
while (p)
{
y = p->y;
if (!g->processed[y] || g->directed)
processEdge(v,y);
if (!g->discovered[y])
{
enQueue(&q,y);
g->discovered[y] = true;
g->parent[y] = v;
}
p = p->next;
}
processVertexLate(v);
}
}
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