[数据结构]图基于邻接矩阵的BFS与DFS的C语言简单实现

上次给大家看了一下图的邻接矩阵的存储。接下来来看下图的广度优先搜索和深度优先搜索。

为了更好的展示BFS和DFS，我把上次的图改了一个边，改成上图那样。
好了，贴代码
由于我们的图广度遍历时需要借助一个队列来实现
所以我们需要用到一个之前实现的队列
把下面这个代码写成queue.c，因为我们图的源文件需要对它导入

#define MAXSIZE 100#define ElemType char#define BOOL int#define TRUE 1#define FALSE 0typedef struct{    ElemType data[MAXSIZE];    int front, rear;}Queue;static void InitQueue(Queue *queue);   //初始化队列static BOOL IsEmpty(Queue *queue); //判断是否为空static void EnQueue(Queue *queue, ElemType x); //入队static void DeQueue(Queue *queue, ElemType *x);    //出队void InitQueue(Queue *queue){    queue->front = 0;    queue->rear = 0;}void EnQueue(Queue *queue, ElemType e){    queue->data[queue->rear] = e;    queue->rear = (queue->rear + 1) % MAXSIZE;}void DeQueue(Queue *queue, ElemType *e){    *e = queue->data[queue->front];    queue->front = (queue->front + 1) % MAXSIZE;}BOOL IsEmpty(Queue *queue){    if (queue->front == queue->rear) {        return TRUE;    } else {        return FALSE;    }}

你可以拿上面的代码跟之前的代码做个比较。其实就是声明函数的那个部分加了static，加这个可以让别的源文件访问，然后main函数去掉了而已。
然后下面是图的代码。

#include <stdio.h>#include <stdlib.h>#define INFINTE 65535#define MAXSIZE 100#include "queue.c"typedef char VertexType;                //顶点类型应由用户定义typedef int EdgeType;                   //边上的权值类型应由用户定义typedef struct graph{    VertexType vexs[MAXSIZE];            //顶点表    EdgeType   arc[MAXSIZE][MAXSIZE];       //邻接矩阵    int numNodes, numEdges;}Graph;int visited[200];void CreateGraph(Graph* graph); //创建图VertexType* FirstAdjVex(Graph graph, VertexType data);  //获取第一邻接点VertexType* NextAdjVex(Graph graph, VertexType data, VertexType adj);   //获取下一邻接点void DFSTraversal(Graph graph); //深度优先遍历void BFSTraversal(Graph graph); //广度优先遍历void DFS(Graph graph, VertexType data); //深度优先搜索void BFS(Graph graph, VertexType data); //广度优先搜索int main(){    int i, j;    Graph graph;    CreateGraph(&graph);    //打印邻接矩阵    for (i = 0; i < graph.numNodes; ++i){        for (j = 0; j < graph.numNodes; ++j){            printf("%d ", graph.arc[i][j]);        }        printf("\n");    }    VertexType* adj = FirstAdjVex(graph, 'A');    VertexType x = *adj;    printf("%c ", x);    adj = NextAdjVex(graph, 'A', x);    x = *adj;    printf("%c ", x);    x = *adj;    adj = FirstAdjVex(graph, 'D');    printf("%c\n", *adj);    for (i = 0; i < 200; ++i){        visited[i] = 0;    }    BFSTraversal(graph);    printf("\n");    for (i = 0; i < 200; ++i){  //访问数组置空        visited[i] = 0;    }    DFSTraversal(graph);    return 0;}void CreateGraph(Graph* graph){    int i, j;    //先把图的邻接矩阵置为0(0表示没边，1表示有边)    for (i = 0; i < graph->numNodes; ++i){        for (j = 0; j < graph->numNodes; ++j){            graph->arc[i][j] = 0;        }    }    //printf("请输入顶点数, 边数：");    //scanf("%d %d", &graph->numNodes, &graph->numEdges);    //getchar();    graph->numNodes = 6;    graph->numEdges = 6;    /*    for (i = 0; i < graph->numNodes; ++i){        printf("请输入顶点：");        scanf("%c", &graph->vexs[i]);        getchar();  //消除空白符    }    */    graph->vexs[0] = 'A';    graph->vexs[1] = 'B';    graph->vexs[2] = 'C';    graph->vexs[3] = 'D';    graph->vexs[4] = 'E';    graph->vexs[5] = 'F';    VertexType start, end;    /*    for (i = 0; i < graph->numEdges; ++i){        printf("请输入起点， 终点：");        scanf("%c %c", &start, &end);        getchar();  //消除空白符        int startIndex, endIndex;        for (j = 0; j < graph->numNodes; ++j){  //找到起始点,终点            if (start == graph->vexs[j]){                startIndex = j;            }            if (end == graph->vexs[j]){                endIndex = j;            }        }        graph->arc[startIndex][endIndex] = 1;        //如果是无向图，需要双向保存        graph->arc[endIndex][startIndex] = 1;    }    */    graph->arc[0][2] = 1;    graph->arc[0][3] = 1;    graph->arc[3][1] = 1;    graph->arc[2][4] = 1;    graph->arc[3][5] = 1;    graph->arc[4][5] = 1;    //如果是无向图，需要保存两个边    /*    graph->arc[2][0] = 1;    graph->arc[3][0] = 1;    graph->arc[1][3] = 1;    graph->arc[4][2] = 1;    graph->arc[5][3] = 1;    graph->arc[5][4] = 1;    */}VertexType* FirstAdjVex(Graph graph, VertexType vex){    //先找到data这个结点    int i, j;    for (i = 0; i < graph.numNodes; ++i){        if (graph.vexs[i] == vex){            for (j = 0; j < graph.numNodes; ++j){                if (graph.arc[i][j] == 1){  //找到第一个邻接点                    return &(graph.vexs[j]);                }            }        }    }    return NULL;    //这步说明没找到}VertexType* NextAdjVex(Graph graph, VertexType vex, VertexType adj){    int vexIndex, adjIndex, i;    for (i = 0; i < graph.numNodes; ++i){        if (graph.vexs[i] == vex){            vexIndex = i;        }        if (graph.vexs[i] == adj){            adjIndex = i;        }    }    for (i = adjIndex + 1; i < graph.numNodes; ++i){  //从当前邻接点的后面寻找        if (graph.arc[vexIndex][i] == 1){            return &(graph.vexs[i]);        }    }    return NULL;    //这步说明没找到}/* 深度优先遍历 */void DFSTraversal(Graph graph){    int i;    for (i = 0; i < graph.numNodes; ++i){        if (visited[graph.vexs[i]] != 1) {            DFS(graph, graph.vexs[i]);        }    }}/* 广度优先遍历 */void BFSTraversal(Graph graph){    int i;    for (i = 0; i < graph.numNodes; ++i){        if (visited[graph.vexs[i]] != 1) {            DFS(graph, graph.vexs[i]);        }    }}/*    广度优先搜索*/void BFS(Graph graph, VertexType vetex){    Queue queue;    InitQueue(&queue);    EnQueue(&queue, vetex);    VertexType adj;    VertexType *p;    visited[vetex] = 1;    while (!IsEmpty(&queue)){        DeQueue(&queue, &vetex);        printf("%c ", vetex);        for (p = FirstAdjVex(graph, vetex); p != NULL; p=NextAdjVex(graph, vetex, adj)){            adj = *p; //应该可以写成*p，但是不行            if (visited[adj] != 1){                EnQueue(&queue, adj);                visited[adj] = 1;            }        }    }}/*    深度优先搜索*/void DFS(Graph graph, VertexType vex){    visited[vex] = 1;    printf("%c ", vex);    VertexType *p;    VertexType x;    for (p = FirstAdjVex(graph, vex); p != NULL; p=NextAdjVex(graph, vex, x)){        x = *p;        if (visited[x] != 1){    //没访问过            DFS(graph, x);        }    }}