#include <iostream>
#include <queue>

#define MaxSize 10
using namespace std;

bool visited[MaxSize]; //全局数组，记录结点是否已补访问

typedef struct edgenode {  //边表结点
	int adjvex;  //邻接点
	int weight;  //权值
	edgenode *next; //下一条边
};

typedef struct vertexnode { //顶点结点
	char data;  //结点数据
	edgenode *fist;  //指向第一条边
}AdjList[MaxSize];

typedef struct AdjListGraph {
	AdjList adjlist;  //邻接表
	int vex;  //顶点数
	int edge; //边数
};

void Init(AdjListGraph &G) {  //初始化为未访问
	for (int i = 0; i < MaxSize; i++) {
		visited[i] = false;
	}
}

int Location(AdjListGraph &G,char c) {  //寻找顶点数据的邻接点
	for (int i = 0; i < G.vex; i++) {
		if (G.adjlist[i].data == c) {
			return i;
		}
	}
	return -1;
}

void Create(AdjListGraph &G) {  //创建图
	cout << "请输入该图的顶点数以及边数：" << endl;
	cin >> G.vex >> G.edge;
	cout << "请输入相关顶点：" << endl;
	for (int i = 0; i < G.vex; i++) {
		cin >> G.adjlist[i].data;
		G.adjlist[i].fist = NULL;
	}
	char a, b;
	int m, n;
	cout << "请输入相关边的顶点：" << endl;
	for (int i = 0; i < G.edge; i++) {
		cin >> a >> b;
		m = Location(G, a);  //寻找顶点号
		n = Location(G, b);

		if (m != -1 && n != -1) {  //寻找到位置
			edgenode *temp = new edgenode;
			temp->adjvex = n;
			temp->next = G.adjlist[m].fist;
			G.adjlist[m].fist = temp;
		}
	}
}

void BFS(AdjListGraph &G,int v) {  //图的广度遍历
	queue <int> q;
	q.push(v);
	int temp;
	int w;
	while (!q.empty()) {  //队列非空
		temp = q.front();  //取对头元素
		if (visited[temp] == false) {  //如果没有被访问
			cout << G.adjlist[temp].data << " ";
			visited[temp] = true;  //设置为已访问 
		}
		q.pop();  //出队列

		edgenode *tp = G.adjlist[temp].fist;
		if (tp != NULL) {
			w = tp->adjvex;
			q.push(w);  //将第一个邻接点入队
			while (tp->next != NULL) {  //存在后续,同样入队列中
				tp = tp->next;
				w = tp->adjvex;
				q.push(w);
			}
		}
	}
}


void BFS_Main(AdjListGraph &G) {  //这个函数的存在是防止不连通图的存在
	for (int i = 0; i < G.vex; i++) {
		if (visited[i] == false) {
			BFS(G,i);
		}
	}
}

int main() {
	AdjListGraph G;
	Init(G);
	Create(G);  //创建图
	BFS_Main(G);

	system("pause");
	return 0;
}

/*
8 7 a b c d e f g h
a b
a f
b c
b d
d e
f g
f h
*/