way：栈，map（或set，只是我想用map）记录是否访问过，放入时记录为已访问，打印，邻接的没访问过先入cur，再入邻接的节点，放入一个邻接的节点后及时break去下一个深度节点。（为什么要放入cur，因为需要遍历到全部节点，而不只是一条）

#include<iostream>
#include<vector>
#include<map>
#include<set>
#include<queue>
#include<stack>
using namespace std;//边结构的描述
class Edge
{
public://边的起始节点Node from;//边的终点节点Node to;//边的权重int weight;
public:Edge(Node from, Node to, int weight){this->from = from;this->to = to;this->weight = weight;}
};//点结构的描述
class Node
{
public://编号值int value;//入度int in;//出度int out;//邻接的点vector<Node> nexts;//邻接的边vector<Edge> edges;
public:Node(){}Node(int value){this->value = value;in = 0;out = 0;}
};//图结构的描述
class Graph
{
public:map<int, Node> nodes;set<Edge> edges;Graph(){}
};//利用边结构描述的图来构建图结构
//[0,7,5]   [from,to,weight]
//[0,1,3]   [from,to,weight]
Graph createGraph(vector<vector<int>> matrix)
{Graph graph;int m = matrix.size();for(int i=0; i<m; i++){int from = matrix[i][0];int to = matrix[i][1];int weight = matrix[i][2];//将起点结构放到图里面if(!graph.nodes.count(from)){Node fromNode(from);graph.nodes[from] = fromNode;}//将终点结构放到图里面if(!graph.nodes.count(to)){Node toNode(to);graph.nodes[to] = toNode;}//将起点和终点的边结构也放到图里面(点可能已经存在过,边一定是新的)Node fromNode = graph.nodes[from];Node toNode = graph.nodes[to];Edge newEdge(fromNode, toNode, weight);fromNode.nexts.push_back(toNode);fromNode.edges.push_back(newEdge);fromNode.out++;toNode.in++;graph.edges.insert(newEdge);}return graph;
}void dfs(Node start)
{map<Node,bool>vis;stack<Node> st;st.push(start);vis[start]=true;cout<<start.value<<" ";while(!st.empty()){Node cur = st.top();st.pop();for(auto next: cur.nexts){if(vis.count(next)==0){st.push(cur);st.push(next);vis[next]=true;cout<<next.value<<" ";break;}}}cout<<endl;
}