无向图的深度优先遍历和广度优先遍历（递归）
queue.h源代码
注释：包括队列数据类型的定义和相关操作
（出队，入队，判断队空，判断队列中是否存在某元素）
int searchQ(LinkQueue &Q,int s) 函数的作用：在将邻接顶点放入队列之前需要先判断队 列中是否已存在此元素，通过查找避免队列中有重复元素。
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include “queen.h”
using namespace std;
//李艳娟实验指导书版本改编，文档在‘文档’文件夹中
//无向无权图—DFS , BFS
#ifndef QUEEN_H_INCLUDED
#define QUEEN_H_INCLUDED
typedef struct Qnode{ //链队结点的类型
int data;
struct Qnode *next;
}Qnode,*QueuePtr;
typedef struct
{ //链队指针类型
QueuePtr front;
QueuePtr rear;
}LinkQueue;
void InitQueue(LinkQueue &Q)
{
Q.front=Q.rear=(QueuePtr)malloc(sizeof(Qnode));
if(!Q.front) exit(1); //存储分配失败
Q.front->next=NULL;
}
void EnQueue(LinkQueue &Q,int e)
{ QueuePtr p;
p=(QueuePtr)malloc(sizeof(Qnode));
p->data=e;
p->next=NULL;
Q.rear->next=p;
Q.rear=p;
}
int QueueEmpty(LinkQueue &Q)
{
return(Q.front==Q.rear? 1:0);
}
void DeQueue(LinkQueue &Q,int &e)
{ QueuePtr p;
if(QueueEmpty(Q))
{
printf(“\n Queue is free!”);
exit(1);
}//if
p=Q.front->next;
e=p->data;
Q.front->next=p->next;
if(Q.front->next==NULL) Q.rear=Q.front;
free(p);
}
int searchQ(LinkQueue &Q,int s){
QueuePtr p=Q.front;
while(p!=NULL){
if(s==p->data)
return 1;
p=p->next;
}
return -1;
}
#endif // QUEEN_H_INCLUDED
main.cpp源代码
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include “queen.h”
using namespace std;
//李艳娟实验指导书版本改编，文档在‘文档’文件夹中
//无向无权图—DFS , BFS
#define MAX_VERTEX_NUM 20 //顶点最大个数
#define MAXSIZE 20
typedef struct ArcNode
{
int adjvex;
struct ArcNode *nextarc;
int weight; //边的权
} ArcNode; //表结点
#define VertexType int //顶点元素类型
typedef struct VNode
{
int degree,indegree;//顶点的度，入度
VertexType data;
ArcNode *firstarc;
} VNode/*头结点*/,AdjList[MAX_VERTEX_NUM];
typedef struct
{
AdjList vertices;
int vexnum,arcnum;//顶点的实际数，边的实际数
} ALGraph;
void CreatALGraph(ALGraph &G)
{
int i,j,k,weight;
ArcNode *s;
printf(“input vexnum and arcnum:”); //输入顶点数和边数
scanf(“%d%d”,&G.vexnum, &G.arcnum);
printf(“input vertex information:”); //输入顶点信息
for(i=0; i<G.vexnum; i++)
{
scanf(“%d”,&(G.vertices[i].data));
G.vertices[i].firstarc=NULL;
}
printf(“input arcs, input the xuhao\n”);
for(k=0; k<G.arcnum; k++)
{
printf(“information of %dth arc: “,k);
//scanf(“%d%d%d”,&i,&j,&weight);
scanf(“%d%d”,&i,&j);
s=(ArcNode*)malloc(sizeof(ArcNode));
s->adjvex=j;
//s->weight=weight;
s->nextarc=G.vertices[i].firstarc;
G.vertices[i].firstarc=s;
s=(ArcNode*)malloc(sizeof(ArcNode));
s->adjvex=i;
//s->weight=weight;
s->nextarc=G.vertices[j].firstarc;
G.vertices[j].firstarc=s;
}
}
void OutputALGraph(ALGraph G)
{
int i;
for(i=0; i<G.vexnum; i++)
{
ArcNode * s;
printf(“%d:%d”,i,G.vertices[i].data); //顶点信息
s=G.vertices[i].firstarc;
while(s)
{
// printf(“\t%d,%d”,s->adjvex,s->weight);
printf(“\t%d”,s->adjvex);
s=s->nextarc;
}
printf(“\n”);
}
}
int LocateVertex(ALGraph G, VertexType v)
{
int i;
for(i=0; i<G.vexnum; i++)
if(G.vertices[i].data==v)
return i;
return -1;
}
int visited[MAXSIZE];
void DFSws(ALGraph &G, int v)
{
ArcNode *p;
printf(“%d “,G.vertices[v].data);
visited[v]=1;
p=G.vertices[v].firstarc;
while (p)
{
if (!visited[p->adjvex]) DFSws(G,p->adjvex);
p=p->nextarc;
}
} //从第v个顶点出发DFS
void DFSTraverse(ALGraph G)
{
int v;
for(v=0; v<G.vexnum; v++)
{
visited[v]=0;
}
for(v=0; v<G.vexnum; v++)
{
if(!visited[v])
DFSws(G,v);
}
printf(“\n”);
}
void BFSTraverse(ALGraph &G)
{
LinkQueue Q;
for(int v=0; v<G.vexnum; v++) visited[v]=0;
InitQueue(Q);
for(int v=0; v<G.vexnum; v++)
if(!visited[v])
{
EnQueue(Q,v);
while(!QueueEmpty(Q))
{
int u;
DeQueue(Q,u);
visited[u]=1;
printf(“%d “,G.vertices[u].data);//visit一下
for(ArcNode *w=G.vertices[u].firstarc; w; w=w->nextarc)
if(!visited[w->adjvex]&&searchQ(Q,w->adjvex)!=1) EnQueue(Q,w->adjvex);
}//while
}//if
}//BFSTraverse
int main()
{
ALGraph G;
CreatALGraph(G);
cout<<“****************”<<endl;
cout<<“图G的邻接表“<<endl;
OutputALGraph(G);
cout<<“****************”<<endl;
cout<<“深度优先遍历顺序“<<endl;
DFSTraverse(G);
cout<<“****************”<<endl;
cout<<“广度优先遍历顺序“<<endl;
BFSTraverse(G);
return 0;
}
程序运行，示例图 图G如下所示：（7顶点，8条边）
