【数据结构】图的广度优先遍历BFS 邻接矩阵实现

//网图（带权值）的邻接矩阵
#include<iostream>
#include<cstring>
#include<queue>
using namespace std;
const int INFINIT = 0x3f3f3f3f;
const int MAXVAX = 100;

template<class T>
class MGraph {
private:
	T * vertex; //数组，用来存放顶点信息
	int ** arc; //二维数组，用来存放邻接矩阵
	int vertexNum, arcNum; //顶点数量 边数
public:
	MGraph(T v[], int n, int e);
	~MGraph();
	void display();
	void BFS(int i,int * visited);
	void BFSTraverse(int * visited);
};

template<class T>
void MGraph<T>::BFS(int i,int * visited){
	queue<int> q;
	visited[i] = 1;
	q.push(i);
	while(!q.empty()){
		int temp = q.front();
		cout<<vertex[temp]<<" ";
		q.pop();
		for(int j=0;j<vertexNum;j++){
			if(!vertex[i]&&arc[i][j]!=0&&arc[i][j]!=INFINIT){
				
				visited[j] = 1;
				q.push(j);
			}
		}

	}
	cout<<"\n";
}
template<class T>
void MGraph<T>::BFSTraverse(int * visited){
	for(int i=0;i<vertexNum;i++){
		visited[i] = 0;
	}
	for(int i=0;i<vertexNum;i++){
		if(!visited[i]){
			BFS(i,visited);
		}
	}
}

template<class T>
MGraph<T>::MGraph(T v[], int n, int e) {
	vertexNum = n;
	arcNum = e;
	vertex = new T[vertexNum];
	//新建一个名为vertex的数组，该数组的元素个数为vertexNum，元素类型为T，用来存放顶点信息

	arc = new int *[vertexNum]; //建立邻接矩阵
	//新建一个名为arc的数组，该数组的元素个数为vertexNum，元素类型为int *，用来存放邻接矩阵
	//其实就是二维数组

	for (int i = 0; i < vertexNum; i++)
		arc[i] = new int[vertexNum];

	for (int i = 0; i < vertexNum; i++) {
		//初始化顶点信息
		vertex[i] = v[i];
	}

	for (int i = 0; i < vertexNum; i++) {
		//初始化邻接矩阵
		for (int j = 0; j < vertexNum; j++) {
			if (i == j) {
				arc[i][j] = 0;
			} else arc[i][j] = INFINIT;
		}
	}

	int vi, vj, w;
	for (int i = 0; i < arcNum; i++) {
		cout << "请输入边的两个顶点和这条边的权值" << endl;
		cin >> vi >> vj >> w; //输入边依附的两个顶点的编号和权值
		arc[vi][vj] = w;
	}
}

template<class T>
void MGraph<T>::display() {

	for (int i = 0; i < vertexNum; i++) {
		cout << vertex[i] << "\t";
	}
	cout << endl;

	for (int i = 0; i < vertexNum; i++) {
		for (int j = 0; j < vertexNum; j++) {
			if (arc[i][j] == INFINIT)
				cout << "∞" << "\t";
			else cout << arc[i][j] << "\t";
		}
		cout << endl;
	}
	cout << endl;

}

template <class T>
MGraph<T>::~MGraph() {
	delete[] vertex;
	for (int i = 0; i < vertexNum; i++) {
		delete[] arc[i];
	}
	delete[] arc;
	cout<<"删除节点数组和邻接矩阵成功！"<<endl;
}

int main() {
	static int visited[MAXVAX] = {0};
	int num,num1;
	cout << "请输入节点的数量：" << endl;
	cin >> num;
	cout << "请输入边的数量：" << endl;
	cin >> num1;
	cin.get();

	char *v[num] = {0};
	memset(v, 0 ,sizeof(v));
	cout << "请输入节点的信息：" << endl;
	int i = num;
	while(i--)
	{
		v[i]=new char[3];
		gets(v[i]);
	}

	cin.sync();
	cin.clear();

	MGraph<char*> mgraph1(v, num, num1);

	mgraph1.display();

	cout<<"v数组的大小为："<<sizeof(v)<<endl;

	mgraph1.BFSTraverse(visited);

	for(int j= 0;j< num;j++)
	{
		delete[] v[j];
	}
//	delete[] v;
//数组v是静态分配的，无需delete
	cout<<"删除节点数组v成功！"<<endl;

	return 0;

}

//int main() {
//	static int visited[MAXVAX];
//	char * v[5] = {(char*)"v0",(char*)"v1",(char*)"v2",(char*)"v3",(char*)"v4"};
//	//	char* v[5] = {"v0", "v1", "v2", "v3", "v4"};
//
//	MGraph<char*> mgraph1(v, 5, 6);
//	//之所以元素类型是char*，是因为输入的是“v0”字符串
//	//由于C语言中没有真正的字符串类型，可以通过字符数组表示字符串，因为它的元素地址是连续的
//
//	mgraph1.display();
//
//	cout<<"v数组的大小为："<<sizeof(v)<<endl;
//	//v[5]是一个有5个元素的数组，元素的类型（指向char类型变量的）指针
//	//一个指针占8个字节，所有v[5]占40个字节
//
//	mgraph1.BFSTraverse(visited);
//
//	return 0;
//}