#include<iostream>
using namespace std;
struct Node {    //结点，用来存储图上结点的信息char data;        //结点名称        Node *next;int loc;//数组下标

};
struct headNode {Node *address;bool flag;//标志，默认为false代表没有被访问(访问过就是true防止重复访问 耶我真机智)
};
class Graph {
private:headNode *root;const int MAX_SIZE = 20;int true_size;void initGraph(char data[], int num);void contact();int search(char goal);void dfs_print(int loc);
public:Graph() { root = NULL; true_size = 0; }Graph(char data[], int num);void add();void print_all();void DFSprint(char item);
};

#include"Graph.h"
Graph::Graph(char data[], int num)
{initGraph(data, num);cout << "图初始化完毕！" << endl;contact();
}
void Graph::contact()
{cout << "请分别输入这" << true_size << "个元素的连接结点：" << endl;int contact_number;for (int i = 0; i < true_size; i++){cout << "请输入连接" << root[i].address->data << "结点的个数：";cin >> contact_number;cout << "请分别输入连接的结点的名称:" << endl;for (int j = 0; j < contact_number;j++){char data;Node *end = root[i].address;while (end->next){end = end->next;}Node *add = new Node();cin >> data;add->data = data;add->loc = search(data);if (add->loc == -1){//错误
            }add->next = NULL;end->next = add;}}
}
int Graph::search(char goal)//-1为查找失败
{int result = -1;for (int i = 0; i < true_size; i++){if (root[i].address->data == goal){result = i;break;}}return result;
}
void Graph::initGraph(char data[],int num)
{true_size = num;root = new headNode[MAX_SIZE];for (int i = 0; i < true_size; i++){root[i].address = new Node();root[i].address->data = data[i];root[i].address->loc = i;root[i].address->next = NULL;root[i].flag = false;}
}
void Graph::add()
{cout << "请输入要添加的元素:" << endl;char data;cin >> data;int loc = search(data);if (loc!= -1){cout << "元素已经存在在图中，请输入添加连接的个数：" << endl;int number;cin >> number;for (int j = 0; j < number; j++){char data;Node *end = root[loc].address;while (end->next){end = end->next;}Node *add = new Node();cin >> data;add->data = data;add->loc = search(data);if (add->loc == -1){cout << "未找到指定元素" << endl;}add->next = NULL;end->next = add;}}else{if (true_size > MAX_SIZE){cout << "图已经超出最大连接长度，添加失败！" << endl;return ;}true_size++;root[true_size].address = new Node();root[true_size].address->data = data;root[true_size].address->loc = true_size;root[true_size].address->next = NULL;}cout << data << "已经成功添加！" << endl;
}
void Graph::print_all()
{    for (int i = 0; i < true_size; i++){cout << "结点:" << root[i].address->data << "连接的结点为：" << endl;Node *p = root[i].address->next;while (p){cout << p->data << " ";p = p->next;}cout << endl;}
}
void Graph::dfs_print(int loc)
{Node *p = root[loc].address;root[loc].flag = true;while (p!= NULL){Node *w = p->next;if ((w!=NULL)&&(root[w->loc].flag == false)){cout << w->data << " ";dfs_print(w->loc);}p = p->next;}
}
void Graph::DFSprint(char item)
{int loc = search(item);if (loc == -1){cout << "错误，未找到结点！" << endl;}else{cout << root[loc].address->data << " ";    dfs_print(loc);}
}

#include"Graph.h"
int main()
{char *graphNode,select;int number;cout << "请输入图中结点个数:";cin >> number;graphNode = new char[number];cout << "请输入结点名称并继续:" << endl;for (int i = 0; i < number; i++){cin >> graphNode[i];}Graph test(graphNode, number);test.add();test.print_all();cout << "请输入开始访问的结点:" << endl;cin >> select;test.DFSprint(select);system("pause");return 0;}

请输入图中结点个数:4
请输入结点名称并继续:
A B C D
图初始化完毕！
请分别输入这4个元素的连接结点：
请输入连接A结点的个数：1
请分别输入连接的结点的名称:
C
请输入连接B结点的个数：1
请分别输入连接的结点的名称:
D
请输入连接C结点的个数：1
请分别输入连接的结点的名称:
A
请输入连接D结点的个数：1
请分别输入连接的结点的名称:
B
请输入要添加的元素:
A
元素已经存在在图中，请输入添加连接的个数：
1
B
A已经成功添加！
结点:A连接的结点为：
C B
结点:B连接的结点为：
D
结点:C连接的结点为：
A
结点:D连接的结点为：
B
请输入开始访问的结点:
A
A C B D 请按任意键继续. . .

测试结果