深度优先搜索算法的实践

如上篇博客所言，最近在学习数据结构中图的知识。按照书中的讲解和伪代码，我自己也编辑了个 深度优先搜索算法。不过是用递归实现的。

本想也把广度优先搜索算法也一起做出来，却发现广度优先算法没有递归的实现。那就需要再一点时间去研究了。等下一篇博客贴出来。

#include <iostream>
#define MAX_VERTEX_NUM 21
using namespace std;
 
typedef struct Graph
{
    int vex[MAX_VERTEX_NUM][MAX_VERTEX_NUM];
    int vexNum;
    int arsNum;
    int visited[MAX_VERTEX_NUM];
}Graph;

void init(Graph *G)
{
    int i, j;
    for (i = 1; i <= G->vexNum; ++i)
    {
        for (j = 1; j <= G->vexNum; ++j)
        {
            G->vex[i][j] = 0;
        }
        G->visited[i] = 0; 
    }
}
void print(Graph *G)
{
    int i, j;
    for (i = 1; i <= G->vexNum; i++)
    {
        for (j = 1; j <= G->vexNum; j++)
        {
            printf("%d ", G->vex[i][j]);
        }
        printf("
");
    }
}

void creat(Graph *G)
{
    int i;
    cout << "please input the num of vex and ars:";
    scanf("%d %d", &G->vexNum, &G->arsNum);
    init(G);
    for (i = 0; i < G->arsNum; ++i)
    {
        int ars1, ars2;
        printf("please input the %d ars :", i+1);
        scanf("%d %d", &ars1, &ars2);
        G->vex[ars1][ars2] = 1;
    }
    print(G);
}

void visit(Graph *G, int vex)
{
    printf("the vex %d has been visited
", vex);
    G->visited[vex] = 1;
}

void DepthFirstSerch(Graph *G, int vex)
{
    int i;
    visit(G, vex);
    for(i = 1; i <= G->vexNum; i++)
    {
        if(G->visited[i] == 0 && G->vex[vex][i] == 1)
            DepthFirstSerch(G, i);
    }

}

int main()
{
    Graph G;
    creat(&G);
    DepthFirstSerch(&G, 1);
    return 0;
}

运行结果如图

 这个程序验证了课本中罗列的一个图的深度优先遍历顺序。（书中的ABCD 均有 1234代替）