求连通图的割点

#include<iostream>
#include<fstream>
using namespace std;
const int gray=1;
const int white=0;
const int black=2;
const int v_num=10;
const int start=0;
int graph[v_num][v_num];
int color[v_num];
int Time;
int discoverTime[v_num];
int rem=0;

int bicompDFS(int v)
{
	color[v]=gray;
	Time++;
	int back=discoverTime[v]=Time;
	for(int w=0;w<v_num;w++)
	{
		if(graph[v][w]==0)
			continue;
		
		if(color[w]==white)
		{
			if(v==start)
				rem++;
			int wBack=bicompDFS(w);
			if(wBack>=discoverTime[v])
			{
				if(v==start&&rem<=1)
				  ;
				else
					cout<<char(v+'A')<<"is articulation points"<<endl;
			}
			back=min(back,wBack);
		}
		else if(color[w]==gray)
		{
			back=min(discoverTime[w],back);
		}
		
	}
	color[v]=black;
	return back;
}
int main()
{
	freopen("input.txt","r",stdin);
	//input graph
	//
	//
	char ch1,ch2;	
	int i,j;
	for(int i=0;i<v_num;i++)
	{
		color[i]=white;
		for(int j=0;j<v_num;j++)
			graph[i][j]=0;
	}
	while(scanf("%c %c\n",&ch1,&ch2)!=EOF)  //输入边
	   graph[ch2-'A'][ch1-'A']=graph[ch1-'A'][ch2-'A']=1;
	
	Time=0;
	
	bicompDFS(start);
	return 0;
}