图的基本遍历算法的实现（BFS & DFS）复习

#include <stdio.h>

#define INF 32767
typedef struct MGraph{
    char vertexs[];
    int edge[][];
    int ver_num, edge_num;
}MGraph;

void create_graph(MGraph *graph)
{
    int i, j;
    getchar();
    for(i = ; i < graph->ver_num; ++i)
        scanf("%c%*c",&(graph->vertexs[i]));

    for(i = ; i < graph->ver_num; ++i)
    {
        for(j = ; j < graph->ver_num; ++j)
        {
            if(i == j)
                graph->edge[i][i] = ;
            else
                graph->edge[i][j] = INF;
        }
    }
    int vi, vj, val;
    for(i = ; i < graph->edge_num; ++i)
    {
        scanf("%d %d %d", &vi, &vj, &val);
        graph->edge[vi][vj] = graph->edge[vj][vi] = val;
    }
}

void print_graph(MGraph graph)
{
    int i,j;
    for(i = ; i < graph.ver_num; ++i)
    {
        for(j = ; j < graph.ver_num; ++j)
        {
            printf("%d\t", graph.edge[i][j]);
        }
        puts("");
    }
}

int vis[];
void dfs(MGraph graph, int vertex)
{
    int i;
    vis[vertex] = ;         //将该结点标记为访问过
    printf("%d -> %c\t", vertex, graph.vertexs[vertex]);    //打印结点信息，当然也可以是其他操作

    for(i = ; i < graph.ver_num; ++i)
    {   //从vertex 到 i 有路径存在，而且 i 结点未被访问过
        if(graph.edge[vertex][i] >  && graph.edge[vertex][i] != INF && !vis[i])
            dfs(graph, i);   //进行dfs遍历
    }
}

void dfstraverse(MGraph graph)
{
    int i;
    for(i = ; i < graph.ver_num; ++i)  //将所有结点标记为未访问过
        vis[i] = ;
    for(i = ; i < graph.ver_num; ++i)  //从每个未被访问过的结点开始进行dfs遍历
        if(!vis[i])
            dfs(graph, i);
}

typedef struct Queue{
    int store[];
    int front, rear;
}Queue;

void InitQueue(Queue *queue)
{
    queue->front = queue->rear = ;
}
void EnQueue(Queue *queue , int i)
{
    if(queue->rear == )
        puts("the queue is full!!");
    else{
        queue->store[queue->rear] = i;
        queue->rear++;
    }
}

int DeQueue(Queue *queue)
{
    if(queue->rear == queue->front)
        printf("the queue is empty!!");
    else{
        queue->front++;
        return queue->store[queue->front-];
    }
}

Queue queue; //定义队列
void bfs(MGraph graph, int vertex)
{
    int i, tmp;
    vis[vertex] = ;
    printf("%d -> %c\t",vertex, graph.vertexs[vertex]);
    EnQueue(&queue, vertex);

    while(queue.front != queue.rear)
    {
        tmp = DeQueue(&queue);
        for(i = ; i < graph.ver_num; ++i)
        {
            if(graph.edge[tmp][i] >  && graph.edge[tmp][i] != INF && !vis[i])
            {
                vis[i] = ;
                printf("%d -> %c\t", i, graph.vertexs[i]);
                EnQueue(&queue, i);
            }
        }
    }
}

void bfstraverse(MGraph graph)
{
    int i;
    InitQueue(&queue);
    for(i = ; i < graph.ver_num; ++i)
        vis[i] = ;
    for(i = ; i < graph.ver_num; ++i)
        if(!vis[i])
            bfs(graph, i);
}

int main()
{
    MGraph graph;
    scanf("%d %d", &(graph.ver_num), &(graph.edge_num));
    create_graph(&graph);
    print_graph(graph);
    dfstraverse(graph);
    puts("");
    bfstraverse(graph);
    return ;
}
/*
4 4
0 1 2 3
0 1 9
1 2 8
2 3 7
3 0 6
 * */

基于邻接矩阵的 DFS & BFS

 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>

 typedef struct ArcNode{
     int adjVex;             //邻接点域
     struct ArcNode *next;   //指针域
 }ArcNode;                   //边表

 typedef struct VertexNode{
     int data;               //顶点域
     struct VertexNode *firstArc;//边表头指针
 }VertexNode, AdjList[];    //顶点表

 typedef struct {
     AdjList adjlist;
     int ArcNum, VertexNum;      //图中的顶点数和边数
 }AdjListGraph;
 /*
  * 创建的是无向图，采用头插法建立边表
  * */
 int create_graph(AdjListGraph *graph)
 {
     int i, j;
     for(i = ; i < graph->VertexNum; ++i)
     {
         graph->adjlist[i].data = i;
         graph->adjlist[i].firstArc = NULL;
     }
     int m, n, val;
     for(i = ; i < graph->ArcNum; ++i)
     {
         puts("the every arc");
         scanf("%d %d", &m, &n);
         ArcNode *tmp1 = (ArcNode*)malloc(sizeof(ArcNode));
         if(tmp1 == NULL)
             return ;
         tmp1->adjVex = n;
         tmp1->next = graph->adjlist[m].firstArc;
         graph->adjlist[m].firstArc = tmp1;

         ArcNode *tmp2 = (ArcNode*)malloc(sizeof(ArcNode));
         if(tmp2 == NULL)
             return ;
         tmp2->adjVex = m;
         tmp2->next = graph->adjlist[n].firstArc;
         graph->adjlist[n].firstArc = tmp2;
     }
     return ;
 }
 int vis[];
 void dfs(AdjListGraph *graph, int vertex)
 {
     ArcNode *p;
     vis[vertex] = ;
     printf("%d\t", graph->adjlist[vertex].data);
     p = graph->adjlist[vertex].firstArc;

     while(p)
     {
         if(!vis[p->adjVex])
             dfs(graph, p->adjVex);
         p = p->next;
     }
 }
 void dfstreverse(AdjListGraph *graph)
 {
     int i;
     for(i = ; i < graph->VertexNum; ++i)
     {
         vis[i] = ;
     }
     for(i = ; i < graph->VertexNum; ++i)
     {
         if(!vis[i])
             dfs(graph, i);
     }
 }

 typedef struct Queue{
     int store[];
     int front, rear;
 }Queue;

 void InitQueue(Queue *queue)
 {
     queue->front = queue->rear=;
 }
 void EnQueue(Queue *queue , int i)
 {
     if(queue->rear == )
         puts("the queue is full!!");
     else{
         queue->store[queue->rear] = i;
         queue->rear++;
     }
 }

 int DeQueue(Queue *queue)
 {
     if(queue->rear == queue->front)
         printf("the queue is empty!!");
     else{
         queue->front++;
         return queue->store[queue->front-];
     }
 }

 Queue queue;
 void bfs(AdjListGraph *graph, int vertex)
 {
     int i, tmp;
     ArcNode *p;
     vis[vertex] = ;
     printf("%d\t", graph->adjlist[vertex].data);

     EnQueue(&queue, vertex);
     while(queue.front != queue.rear)
     {
         tmp = DeQueue(&queue);
         p = graph->adjlist[tmp].firstArc;
         while(p)
         {
             if(!vis[p->adjVex])
             {
                 vis[p->adjVex] = ;
                 printf("%d\t", graph->adjlist[p->adjVex].data);
                 EnQueue(&queue, p->adjVex);
             }
             p = p->next;
         }

     }
 }

 void bfstreverse(AdjListGraph *graph)
 {

     InitQueue(&queue);
     int i;
     for(i = ; i < graph->VertexNum; ++i)
         vis[i] = ;
     for(i = ; i < graph->VertexNum; ++i)
         if(!vis[i])
             bfs(graph, i);
 }
 int main()
 {
     AdjListGraph graph;
     int arc_num, ver_num;
     puts("input the arc_num & ver_num\n");
     scanf("%d %d", &arc_num, &ver_num);
     graph.ArcNum = arc_num;
     graph.VertexNum = ver_num;
     create_graph(&graph);
     dfstreverse(&graph);
     bfstreverse(&graph);
     return ;
 }

基于邻接表的 DFS & BFS

手写又不熟了，多多看，多多练！