无向图两顶点的连通性及删除边

#include

using namespace std;

#define MAX_VERTEX_NUM 20

#define OK 1

#define ERROR 0

#define OVERFLOW -1

#define INIT_SIZE 50

#define INCREMENT 10

typedef enum{ DG, DN, UDG, UDN } GraphKind;

typedef int status;

typedef int ElemType;

typedef struct ArcNode // 弧结点

{ int adjvex; //邻接点域，存放与Vi邻接的点在表头数组中的位置struct ArcNode *nextarc; //链域，指示依附于vi的下一条边或弧的结点，}ArcNode;

typedef struct VNode //表头结点

{ char vexdata; //存放顶点信息

struct ArcNode *firstarc; //指示第一个邻接点

}VNode,AdjList[MAX_VERTEX_NUM];

typedef struct { //图的结构定义

AdjList vertices; //顶点向量

int vexnum, arcnum;

// GraphKind kind=0; // 图的种类标志

} MGraph;

int LocateVex(MGraph &G,char v){

for(int i=0;i

if(G.vertices[i].vexdata==v)

return i;

}

return -1;

}

void CreateGraph(MGraph &G)

{// 生成图G的存储结构-邻接表无向图

cout<<"输入顶点数、边数:"<

cin >> G.vexnum >> G.arcnum ; // 输入顶点数、边数和图类

// G.vexnum=5;G.arcnum=7;

cout<<"输入顶点:"<

for (int i=0; i

// 构造顶点数组：

cin>> G.vertices[i].vexdata; // 输入顶点

G.vertices[i].firstarc = NULL;

}

cout<<"输入各边:"<

for (int k=0; k

{

char sv,tv;

cin>>sv>> tv; // 输入一条边（弧）的始点和终点

i = LocateVex(G, sv);

int j = LocateVex(G, tv);// 确定sv和tv在G中位置，即顶点在G.vertices中的序号

ArcNode * pi = new ArcNode;

ArcNode * pj = new ArcNode;

if (!pi)

exit(-1);

if (!pj)

exit(-1);

pi -> adjvex = j;

// 对弧结点赋邻接点"位置

pi -> nextarc = G.vertices[i].firstarc;//头插法，将tv结点插入到第i个单链表中

G.vertices[i].firstarc = pi; // 插入链表G.vertices[i]

pj -> adjvex = i;

pj -> nextarc = G.vertices[j].firstarc;

G.vertices[j].firstarc = pj;

}

cout<<"构造成功!"<

}

//删除连接x y的边

status Deleteside(MGraph &G,int x,int y)

{

ArcNode * p=G.vertices[x].firstarc;

ArcNode * q=G.vertices[x].firstarc;

while(p&&p->adjvex!=y)

{

q=p;

p=p->nextarc;

}

if(!p)

return 0;

if (p==G.vertices[x].firstarc)

{

G.vertices[x].firstarc=p->nextarc;

}

else

q->nextarc=p->nextarc;

delete p;

p=G.vertices[y].firstarc;

q=G.vertices[y].firstarc;

while(p&&p->adjvex!=x)

{

q=p;

p=p->nextarc;

}

if(!p)

return 0;

if (p==G.vertices[y].firstarc)

{

G.vertices[y].firstarc=p->nextarc;

}

else

q->nextarc=p->nextarc;

delete p;

return 1;

}

typedef struct Node

{

int data;

struct Node *next;

}QNode,*QueuePtr;

typedef struct

{

QueuePtr front;

QueuePtr rear;

}LinkQueue;

bool visited[10];

ArcNode *nextnode=NULL;//全局变量

//得到i号顶点的第一个邻接点

int FirstAdjVex(MGraph &g,int i){

ArcNode *p;

p=g.vertices[i].firstarc;

if(!p) return -1;

return(p->adjvex);

}

//得到i号顶点的下一个邻接点

int NextAdjVex(MGraph &g,int i,int w){

if(!w) return -1;

ArcNode *p;

p=g.vertices[i].firstarc;

while (p&&p->adjvex!=w)

{

p=p->nextarc;

}

if (!p||!p->nextarc)

{

return -1;

}

int m=p->nextarc->adjvex;

return m;

}

int pathcount=0;

void Append(MGraph G,char *PA TH,int v)

{

PATH[pathcount]=G.vertices[v].vexdata;

pathcount++;

}

void Delete(char *PATH,int v)

{

pathcount--;

}

bool found=false;

void DFSearch(MGraph &G, int v, int s,char* PATH) {

if (found)

{

return;

}

visited[v] = true;// 访问第v 个顶点，并置访问标志

Append(G,PATH, v);//把顶点v加入路径

for (int w=FirstAdjVex(G, v);w!=-1&&!found;w=NextAdjVex(G,v,w)) {

if (w==s)

{

found =true;

Append(G,PA TH, w);

return;//exit(1);

}//找到退出

else if(!visited[w])

DFSearch(G,w, s,PA TH);//加入w

} //end for

if (!found)

Delete(PA TH,v);

}

int main()

{

MGraph G;

CreateGraph(G);

// Deleteside(G,0,2);

Deleteside(G,0,1);

char PATH[20];

DFSearch(G,0,2,PATH);

if (found)

{

cout<<"c"<

}

else

cout<<"d"<

return 0;

}