Breadth First Search Problems

[nebu]

Can you tell me whats wrong with this BFS program with a adjacency list implementation o the graph...

i cant seem to find anything wrong



enum COLORS{WHITE,GRAY,BLACK};

typedef struct __q
{
int key;
struct __q *next;
}queue;

typedef struct __g
{
int BFScount;
int parent;
int level;
enum COLORS state;
queue *adjacent;
}graph;

void enqueue(queue *q,int val)
{
queue *tmp = (queue*)malloc(sizeof(queue));
tmp->next = NULL;
tmp->key = val;
if(q==NULL)
{
q = tmp;
return;
}
while(q->next!=NULL)
q = q->next;
q->next = tmp;
}

int dequeue(queue *q)
{
queue *m = q;
if(q==NULL)
return;
q = q->next;
int val = m->key;
free(m);
return val;
}

void BFS(graph *g,int source,int n)
{
int i;
for(i=0;i<n;i++)
{
g[i].state = WHITE;
g[i].parent = -1;
g[i].level = INT_MAX;
}
g[source].state = GRAY;
g[source].parent = source;
g[source].level = 0;
queue *q = NULL;
enqueue(q,source);
while(q!=NULL)
{
int u = dequeue(q);
queue *v = g[u].adjacent;
while(v!=NULL)
{
if(g[v->key].state == WHITE)
{
g[v->key].state = GRAY;
g[v->key].level = g[u].level + 1;
g[v->key].parent = u;
enqueue(q,v->key);
}
v = v->next;
}
g[u].BFScount++;
g[u].state = BLACK;
}
}

[mike_g]

Perhaps a compliable program, or a little explanation would help. Do you get any errors? Or are you getting stuck in a loop?