第六章 6.5 图的遍历

深度优先搜索

采用邻接矩阵表示图的深度优先搜索遍历

#include<bits/stdc++.h>
using namespace std;
#define MaxInt 32767
#define MVNum 100
#define OK 1
bool visited[MaxInt];
typedef char VerTexType;
typedef int ArcType;
typedef int Status ;

typedef struct{
    VerTexType vexs[MVNum];//存储顶点 
    ArcType arcs[MVNum][MVNum];//邻接矩阵 
    int vexnum,arcnum;//图的当前顶点数和边数 
}AMGraph;

int LocateVex(AMGraph G,char v1)
{
    for(int i = 0; i < G.vexnum  ; i ++)
    {
        if(G.vexs[i] == v1-'0')
            return i;        
    }    
} 

Status CreateUDN(AMGraph &G)
{
    char v1,v2;
    int w,i,j;
    cin>>G.vexnum>>G.arcnum; //读入图的顶点和边数
    for( i = 0; i < G.vexnum ; i ++)
        cin>>G.vexs[i];
    for( i = 0; i < G.vexnum ; i ++)
        for( j = 0; j < G.vexnum ; j ++)
            G.arcs[i][j] = MaxInt;//初始化邻接矩阵，边的权值均置为极大值MaxInt
    for(int k = 0; k < G.arcnum ; k ++)
    {
        cin>>v1>>v2>>w;//输入一条边的顶点和权值 
        i = LocateVex(G,v1);
        j = LocateVex(G,v2);
        G.arcs[i][j] = G.arcs[j][i] = w;    
    } 
    return OK;
}

void DFS_AM(AMGraph G,int v)
{
    cout<<v;
    visited[v] = true;//访问第v个顶点，并将标志数组置为true; 
    int w;
    for(w = 0; w < G.vexnum ; w ++)//依次检查邻接矩阵v所在的行 
    {
        if(G.arcs[v][w] != 0&& !visited[w])
        {
            DFS_AM(G,w);
        }
    }
}

int main()
{
    AMGraph G;
    CreateUDN(G);
    DFS_AM(G,1);
    return 0;
}

采用邻接表表示图的深度优先搜索遍历

#include<bits/stdc++.h>
using namespace std;

#define MVNum 100
bool visited[MVNum];
#define OK 0
typedef int OhterInfo;
typedef int VerTexType;
typedef int Status;
typedef struct ArcNode{//边结点 
    int adjvex;//相邻顶点信息 
    struct ArcNode *nextarc;//下一条边的指针 
    OhterInfo info;//权值 
}ArcNode;

typedef struct VNode{//存储顶点信息 
    VerTexType data;
    ArcNode *firstarc;//第一条依附该顶点的边的指针 
}VNode,AdjList[MVNum];

typedef struct{
    AdjList vertice;//结构体数组 
    int vexnum,arcnum;//图的当前顶点数和边数 
}ALGraph;

int LocateVex(ALGraph G,char ch)
{
    for(int i = 0; i < G.vexnum ; i ++)
        if(G.vertice[i].data  == ch-'0')
            return i;
}
Status CreateUDG(ALGraph &G)
{
    char v1,v2;
    ArcNode *p1,*p2;
    cin>>G.arcnum>>G.vexnum ;//读入总边数和总的顶点数
    int i,j,w;
    for(i = 0; i < G.vexnum  ; i ++)
    {
        cin>>G.vertice[i].data ;
        G.vertice[i].firstarc = NULL;
    }
    for(i = 0; i < G.arcnum ; i ++)
    {
        cin>>v1>>v2>>w;
        i = LocateVex(G,v1);
        j = LocateVex(G,v2);
        p1 = new ArcNode;
        p1->nextarc = G.vertice[i].firstarc ;
        p1->adjvex = j;
        p1->info = w;
        G.vertice[i].firstarc = p1;
        
        p2 = new ArcNode;
        p2->nextarc = G.vertice[j].firstarc ;
        p2->adjvex = i;
        p2->info = w;
        G.vertice[j].firstarc = p2;
     } 
    return OK;
}

void DFS_AL(ALGraph G,int v)
{
    cout<<v;
    int w;
    visited[v] = true;
    ArcNode *p;
    p = G.vertice[v].firstarc ;//p指向v的边链表的第一个边结点 
    while(p !=NULL)//边结点非空 
    {
        w = p->adjvex ;
        if(!visited[w])//如果未被访问，则递归调用 
            DFS_AL(G,w);
        p = p->nextarc ;//指向下一个边结点 
    }
    return;
}

int main()
{
    ALGraph G;
    CreateUDG(G);
    DFS_AL(G,1);
    return 0;
}