너비 우선 탐색 (breath firtst search)

#define MAX_VERTICES 50
#define TRUE 1
#define FALSE 0
short intvidited[MAX_VERTICES];

typedef struct node* node_pointer;
typedef struct node{
 int vertex;
 struct node* link;
};
typedef struct queue* queue_pointer;
typedef struct queue{
 int vertex;
 queue_pointer link;
};
void addq(queue_pointer*, queue_pointer*,int);
int deleteq(queue_pointer*);

void bfs(int v){
 node_pointer w;
 queue_pointer front,rear;
 front=rear=NULL;

 printf("%5d",v);
 visited[v]=TRUE;
 addq(&front,&rear,v);
 while(front){
  v=deleteq(&front);
  for(w=graph[v]; w; w=w->link)
   if(visited[w->vertex]){
    printf("%5d",w->vertex);
    addq(&front,&rear,w->vertex);
    visited[w->vertex]=TRUE;
   }
 }
}