图BFS

图的BFS

#include<stdio.h>#include<stdlib.h>#define MAX 100  #define initial 1#define waiting 2#define visited 3int n;    int adj[MAX][MAX];int state[MAX]; void create_graph();void BF_Traversal();void BFS(int v);int queue[MAX], front = -1,rear = -1;void insert_queue(int vertex);int delete_queue();int isEmpty_queue();int main(){    create_graph();    BF_Traversal();    return 0;}void BF_Traversal(){    int v;    for(v=0; v<n; v++)         state[v] = initial;    printf("Enter Start Vertex for BFS: \n");    scanf("%d", &v);    BFS(v);}void BFS(int v){    int i;    insert_queue(v);    state[v] = waiting;    while(!isEmpty_queue())    {        v = delete_queue( );        printf("%d ",v);        state[v] = visited;        for(i=0; i<n; i++)        {            if(adj[v][i] == 1 && state[i] == initial)             {                insert_queue(i);                state[i] = waiting;            }        }    }    printf("\n");}void insert_queue(int vertex){    if(rear == MAX-1)        printf("Queue Overflow\n");    else    {        if(front == -1)             front = 0;        rear = rear+1;        queue[rear] = vertex ;    }}int isEmpty_queue(){    if(front == -1 || front > rear)        return 1;    else        return 0;}int delete_queue(){    int delete_item;    if(front == -1 || front > rear)    {        printf("Queue Underflow\n");        exit(1);    }    delete_item = queue[front];    front = front+1;    return delete_item;}void create_graph(){    int count,max_edge,origin,destin;    printf("Enter number of vertices : ");    scanf("%d",&n);    max_edge = n*(n-1);    for(count=1; count<=max_edge; count++)    {        printf("Enter edge %d( -1 -1 to quit ) : ",count);        scanf("%d %d",&origin,&destin);        if((origin == -1) && (destin == -1))            break;        if(origin>=n || destin>=n || origin<0 || destin<0)        {            printf("Invalid edge!\n");            count--;        }        else        {            adj[origin][destin] = 1;        }    }}