数据结构-图的深度优先遍历方式（非递归，领接表存储）

#include
#include
 
//表结点，采用邻接表存储图
#include
#include
#include
using namespace std;
//表结点
struct ArcNode {
    ArcNode * next; //下一个关联的边
    int adjvex;   //保存弧尾顶点在顶点表中的下标
};
//顶点表
struct Vnode {
    string data; //顶点名称
    ArcNode * firstarc; //第一个依附在该顶点边
};
class Graph_DG {
private:
    int vexnum; //图的顶点数
    int edge;   //图的边数
    int * indegree; //每条边的入度情况
    Vnode * arc; //邻接表
public:
    Graph_DG(int, int);
    ~Graph_DG();
    //检查输入边的顶点是否合法
    bool check_edge_value(int,int);
    //创建一个图
    void createGraph();
    //打印邻接表
    void print();
    //进行拓扑排序,Kahn算法
    bool topological_sort();
    //进行拓扑排序，DFS算法
    bool topological_sort_by_dfs();
    void dfs(int n,bool * & visit, stack & result);
};
//初始化 vexnum:顶点个数，edge：边数
Graph_DG::Graph_DG(int vexnum, int edge)
{
	
	this->vexnum = vexnum;
    this->edge = edge;
	
	this->arc = new Vnode[this->vexnum];
	
	this->indegree = new int[this->vexnum]; //每个顶点的入度数目
	
	for (int i = 0; i < this->vexnum; i++) {
        this->indegree[i] = 0;
        this->arc[i].firstarc = NULL;
        this->arc[i].data = "v" + to_string(i + 1);
    }
}
void Graph_DG::createGraph() {
    int count = 0;
    int start, end;
    cout << "输入每条起点和终点的顶点编号（从1开始编号）" << endl;
    while (count != this->edge) {
        cin >> start;
        cin >> end;
        //检查边是否合法
        while (!this->check_edge_value(start, end)) {
            cout << "输入的顶点不合法，请重新输入" << endl;
            cin >> start;
            cin >> end;
        }
        //声明一个新的表结点
        ArcNode * temp = new ArcNode;
        temp->adjvex = end - 1;
        temp->next = NULL;
        //如果当前顶点的还没有边依附时，
        if (this->arc[start - 1].firstarc == NULL) {
            this->arc[start - 1].firstarc = temp;
        }
    else {
            ArcNode * now = this->arc[start - 1].firstarc;
            while(now->next) {
                now = now->next;
            }//找到该链表的最后一个结点
            now->next = temp;
        }
        ++count;
    }
}
void Graph_DG::print() {
    int count = 0;
    cout << "图的邻接矩阵为：" << endl;
    //遍历链表，输出链表的内容
    while (count != this->vexnum) {
        //输出链表的结点
        cout << this->arc[count].data<<" ";
        ArcNode * temp = this->arc[count].firstarc;
        while (temp) {
            cout<<"<"<< this->arc[count].data<<","<< this->arc[temp->adjvex].data<<"> ";
            temp = temp->next;
        }
        cout << "^" << endl;
        ++count;
    }
}
//非递归的方式去深度优先遍历图
 
void DFS(Graph_DG G,int startnode)
{
	vector<int> visit(vexnum,0);
	
	stack<int> s;
 
    s.push(startnode);
 
    visit[startnode] =1;
	
	ArcNode * temp = this->arc[startnode].firstarc;
	
	while(!s.empty())
	{
		temp =this->arc[s.top()].firstarc;  //栈顶
		while(temp)   
		{
			if(visit[temp->adjvex]==0)  
			{
				visit[temp->adjvex]==1;
				printf("2%d");
				
				s.push(temp->adjvex);
				
				temp=this->arc[temp->adjvex].firstarc;
				
			}
			
			else //
			{
				
				temp =temp->next;
			}	
			
		}
		
		if(temp==NULL)
		{
			s.pop();
		}
		
	}
	
}