如何验证图的连通性？

#include<iostream>
#include<queue>
#include <stdio.h>
 
using namespace std;
#define MAX_VNUM 10
 
typedef struct
{
	int weight;
}Adj,AdjMatrix[MAX_VNUM][MAX_VNUM];
 
typedef struct
{
	AdjMatrix adjM;
	int vNum;
}adjGraph;
 
//创建一个图,节点从0开始,注意传入引用
void CreateGraph(adjGraph &G)
{
	cout<<"输入节点个数："<<endl;
	cin>>G.vNum;
	cout<<"输入图的邻接矩阵："<<endl;
	for (int i=0;i<G.vNum;i++)
	{
		for (int j=0;j<G.vNum;j++)
{
			cin>>G.adjM[i][j].weight;
		}
	}
}
 
//输出一个图
void print(adjGraph G)
{
	for(int i=0;i<G.vNum;i++)
	{
		for(int j=0;j<G.vNum;j++)
		{
			cout<<G.adjM[i][j].weight<<" ";
		}
		cout<<endl;//将换行流写入输出流，清空输出缓冲区
	}
}
 
 
//warshall算法判断图的连通性
bool connectivityWarshall(adjGraph G)
{
	adjGraph temp;//临时判断矩阵
	temp.vNum = G.vNum;
 
	//初始化临时判断矩阵
	for (int i =0;i<temp.vNum;i++)
	{
		for(int j=0;j<temp.vNum;j++)
		{
			if (G.adjM[i][j].weight)
				temp.adjM[i][j].weight = 1;
			else
				temp.adjM[i][j].weight = 0;
		}
		temp.adjM[i][i].weight = 1;
	}
 
//矩阵乘法算法Warshall,R(a)
for (int a =0;a<temp.vNum;a++)
{
	for (int b=0;b<temp.vNum;b++)
	{
		if(temp.adjM[a][b].weight)
		{
			for (int c = 0;c<temp.vNum;c++)
			{
				if (temp.adjM[c][a].weight)
					temp.adjM[c][b].weight = 1;
			}
		}
	}
 }
 
	//进行判断
for (int i=0;i<temp.vNum;i++)
{
		for (int j=0;j<temp.vNum;j++)
		{
			if (!temp.adjM[i][j].weight)
				return false;
		}
	}
	return true;
}
 
 
//广度优先搜索判断连通性
bool connectivityBFS(adjGraph G)
{
	queue<int> q; //明白队列用途？
	bool visit[MAX_VNUM]; //访问数组
	int count = 0;
	memset(visit,0,sizeof(visit));
	q.push(0); //0节点入队列
 
	while(!q.empty())
	{
		int v = q.front();
		visit[v] = true;
		q.pop();
		count++;
 
		//与联通且没有被访问过节点入队列
		for (int i =0;i<G.vNum;i++)
{
			if (G.adjM[v][i].weight)
			{
				if(!visit[i])
				{
					q.push(i);
				}
			}
		}
	}
 
	if (count == G.vNum) 
return true;
	else 
return false;
}
 
//深度优先搜索判断图的连通性,传递数组会改变值,visit需初始化
void dfs_visit(adjGraph G,int firstNode,bool visit[])
{
	visit[firstNode] = 1;
	for(int i=0; i<G.vNum;i++)
	{
		if(G.adjM[firstNode][i].weight & !visit[i])
		dfs_visit(G,i,visit);
	}
}
 
bool connectivityDFS(adjGraph G)
{
	bool visit[MAX_VNUM]; //访问数组
	memset(visit,0,sizeof(visit));
	dfs_visit(G,0,visit); //从0节点开始访问
 
for(int i=0;i<G.vNum;i++)
	{
		if (visit[i] == false) return false;
	}
	return true;
}
 
int main()
{
	adjGraph G;
	CreateGraph(G);
	//print(G);
 
	if (connectivityWarshall(G)) cout<<"连通"<<endl;
	else cout<<"不连通"<<endl;
	system("pause");
	return 0;
}

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