数据结构_图_求有向图的强连通分量

'head.h'

#include<iostream>using namespace std;#define MAX_VEX_NUM 20class ArcNode//记录一条弧 {public:ArcNode();int headvex,tailvex;ArcNode *hlink,*tlink;};ArcNode::ArcNode(){headvex=tailvex=0;hlink=tlink=NULL;}class VexNode//记录一个顶点连接的所有弧{public:VexNode();bool visited;char vexname;ArcNode *firstin,*firstout;};VexNode::VexNode(){visited=false;firstin=firstout=NULL;}class VexBox//顶点集合{public:VexBox();VexNode vexlist[MAX_VEX_NUM];int vexnum;};VexBox::VexBox(){vexnum=0;}class Graph//图类{public:void ShowGraph();//接口函数private:void GetVexList();//得到顶点列表void CreatGraph();//建图void Print();//打印图信息void StrongComp();//求强连通分量void DFSHead(int);//正向DFSvoid DFSTail(int);//反向DFSVexBox vbox;int count,finished[MAX_VEX_NUM],ans[MAX_VEX_NUM],nans;};void Graph::ShowGraph()//接口函数{GetVexList();//得到顶点列表CreatGraph();//建图Print();//打印图信息StrongComp();//求强连通分量}void Graph::GetVexList()//得到顶点列表{cout<<"Please Input Vertexes :"<<endl<<endl;char name;while(cin>>name){vbox.vexlist[vbox.vexnum++].vexname=name;}cin.clear();}void Graph::CreatGraph()//建图{cout<<"Please Input Arces :"<<endl<<endl;int head,tail;ArcNode * newnode,*p;while(cin>>tail>>head){newnode=new ArcNode;newnode->headvex=head;newnode->tailvex=tail;p=vbox.vexlist[tail].firstout;if(p==NULL){vbox.vexlist[tail].firstout=newnode;}else{while(p->tlink!=NULL){p=p->tlink;}p->tlink=newnode;}p=vbox.vexlist[head].firstin;if(p==NULL){vbox.vexlist[head].firstin=newnode;}else{while(p->hlink!=NULL){p=p->hlink;}p->hlink=newnode;}}cin.clear();}void Graph::Print()//打印图信息{ArcNode *p;for(int i=0;i<vbox.vexnum;i++){cout<<vbox.vexlist[i].vexname<<endl;p=vbox.vexlist[i].firstout;while(p!=NULL){cout<<"\t"<<vbox.vexlist[p->tailvex].vexname<<"->"<<vbox.vexlist[p->headvex].vexname<<endl;p=p->tlink;}}}void Graph::StrongComp()//求强连通分量{count=0;for(int i=0;i<vbox.vexnum;i++){if(vbox.vexlist[i].visited==false)DFSHead(i);}for(int i=0;i<vbox.vexnum;i++)vbox.vexlist[i].visited=false;for(int i=count-1;i>=0;i--){if(vbox.vexlist[i].visited==false){nans=0;DFSTail(i);if(nans>0){cout<<vbox.vexlist[ans[0]].vexname;for(int i=1;i<nans;i++)cout<<"<->"<<vbox.vexlist[ans[i]].vexname;cout<<endl;}}}}void Graph::DFSHead(int k)//正向DFS{vbox.vexlist[k].visited=true;ArcNode *p=vbox.vexlist[k].firstout;while(p!=NULL){if(vbox.vexlist[p->headvex].visited==false)DFSHead(p->headvex);p=p->tlink;}finished[count++]=k;}void Graph::DFSTail(int k)//反向DFS{ans[nans++]=k;vbox.vexlist[k].visited=true;ArcNode *p=vbox.vexlist[k].firstin;while(p!=NULL){if(vbox.vexlist[p->tailvex].visited==false){DFSTail(p->tailvex);}p=p->tlink;}}

'main.cpp'

#include"head.h"int main(){Graph g;g.ShowGraph();system("pause");}