用邻接表实现DFS和BFS

#include <stdio.h>
#include <stdlib.h>
#define MAXVERTEX 10
typedef char VertexType;                //顶点类型
typedef int EdgeType;                   //边的类型
typedef int ElemType;                   //队列中元素类型
typedef struct EdgeNode
{
    int adjvex;
    EdgeType weight;
    struct EdgeNode *next;
}EdgeNode;                              //在邻接表中存放邻接顶点下标值的结点
typedef struct VertexNode
{
    int Flag;
    int vertex;
    VertexType data;
    EdgeNode *firstedge;
}VertexNode,AdjList[MAXVERTEX];         //定义一个MAXVERTEX个顶点的邻接表
typedef struct GraphAdjList
{
    AdjList adjList;
    int numVertex;
    int numEdge;
}GraphAdjList;                          //定义一个图

typedef struct QNode
{
    ElemType qData;
    struct QNode *nextNode;
}QNode;                                 //定义队列的结点
typedef struct QueueList
{
    QNode *front;
    QNode *rear;
}QueueList,*queue;                      //定义一个队列


                                        //初始化队列
void InitQueue(QueueList *Q)
{
    Q->front = (QNode*)malloc(sizeof(QNode));
    if( Q->front == NULL )
    {
        printf("Error!");
        exit(0);
    }
    Q->rear = Q->front;
//    Q->rear = NULL;
    Q->front->nextNode = NULL;
}

                                        //插入一个结点到队列
void InsertQueue(QueueList *Q,ElemType *e)
{
    QNode *p;
    p = (QNode *)malloc(sizeof(QNode));
    p->qData = *e;
    p->nextNode = NULL;
    Q->rear->nextNode = p;
    Q->rear = p;
}

                                        //删除队列中的结点(出队列)
void DeleteQueue(QueueList *Q,ElemType *e)
{
    QNode *s;
    if(Q->front == Q->rear)
    {
        return;
    }
    s = Q->front->nextNode;
    *e = s->qData;
    Q->front->nextNode = s->nextNode;
    if(Q->front->nextNode == NULL)
    {
        Q->rear = Q->front;
    }
    free(s);
    return;
}

void CreateGraph(GraphAdjList *G)           //构建一个我们要遍历的图
{
    int i = 0,j = 0,k = 0;
    EdgeNode *s;
    VertexType c;
    printf("请输入图的顶点数和边数,中间用英文逗号隔开 :
");
    scanf("%d,%d",&G->numVertex,&G->numEdge);
    printf("请输入各个顶点中存放的数据:
");
    fflush(stdin);
    scanf("%c",&c);
    while(i < G->numVertex)
    {
        if(c == '
')
        {
            break;
        }
        G->adjList[i].data = c;
        G->adjList[i].Flag = 0;
        G->adjList[i].vertex = i;
        G->adjList[i].firstedge = NULL;
        i++;
        scanf("%c",&c);
    }
        fflush(stdin);
        for(k = 0;k < G->numEdge;k++)
        {
            printf("请输入边Vi~Vj依附的顶点下标 i 和 j :
");
            scanf("%d,%d",&i,&j);
            s = (EdgeNode*)malloc(sizeof(EdgeNode));
            s->adjvex = j;
            s->next = G->adjList[i].firstedge;
            G->adjList[i].firstedge = s;
            s = (EdgeNode*)malloc(sizeof(EdgeNode));
            s->adjvex = i;
            s->next = G->adjList[j].firstedge;
            G->adjList[j].firstedge = s;
        }
}
                                            //查看邻接表是否构建的正确,这个函数只是为了验证
void print(GraphAdjList *G)
{
    int i = 0;
    EdgeNode *p;
    for(i = 0;i < G->numVertex;i++)
    {
        printf("
 %d->",i);
        p = G->adjList[i].firstedge;
        while(p)
        {
            printf("%d->",p->adjvex);
            p = p->next;
        }
        printf("End
");
    }
}

                                            //DFS遍历
void DFSTraverse(GraphAdjList *G,int i)
{
    int j = 0;
    EdgeNode *p;
    G->adjList[i].Flag = 1;
    printf("%c->",G->adjList[i].data);
    p = G->adjList[i].firstedge;
    while(p != NULL)
    {
        if(G->adjList[p->adjvex].Flag == 0)
        {
            DFSTraverse(G,p->adjvex);
        }
        p = p->next;
    }
}
                                            //判断队列是否为空
int QueueEmpty(QueueList *Q)
{
    if(Q->front == Q->rear)
        return 0;
    else
        return 1;
}
                                            //BFS遍历
void BFSTraverse(GraphAdjList *G)
{
    int i = 0,k = 0,flag = 0;
    EdgeNode *s;
    QueueList Q;
    InitQueue(&Q);
    for(i = 0;i < G->numVertex;i++)
    {
        G->adjList[i].Flag = 0;
    }
    for(i = 0;i < G->numVertex;i++)
    {
        if(G->adjList[i].Flag == 0)
        {
            G->adjList[i].Flag = 1;
//            printf("%c ",G->adjList[i].data);
            InsertQueue(&Q,&i);
            while(QueueEmpty(&Q))
            {
                DeleteQueue(&Q,&i);
                printf("%c->",G->adjList[i].data);
                s = G->adjList[i].firstedge;
                while(s != NULL)
                {
                    k = s->adjvex;
                    if(G->adjList[k].Flag == 0)
                    {
                        G->adjList[k].Flag = 1;
//                        printf("%c ",G->adjList[k].data);
                        InsertQueue(&Q,&(s->adjvex));
                    }
                    s = s->next;
                }

            }
        }
    }
    printf("End
");
}

int main()
{
    int k = 0;                               //深度优先遍历从第1个顶点(按输入顺序)开始
    GraphAdjList *G;
    CreateGraph(G);
    printf("
顶点的邻接表为:
");
    print(G);                                //按照头插法得到的邻接表
    printf("
DFS的结果是:
");
    DFSTraverse(G,k);                        //深度优先遍历
    printf("End
");
    printf("
BFS的结果是:
");
    BFSTraverse(G);                         //广度优先遍历
    return;
}

  

原文地址:https://www.cnblogs.com/devinblog/p/4177045.html