测试数据基于上图，新增4->1的路径。程序存在内存泄漏。
使用时可以修改depth_first_search第二个参数，指定开始遍历的结点，只适用与连通图。如果错误，欢迎指正！！
#include <iostream>
#include <stack>
using namespace std;
/***************************************
* 图的深度优先遍历
* 基于邻接链表的非递归实现
**************************************/
typedef char vertex_t; //结点数据类型
//边结点
typedef struct _tag_edge_node_t
{
int node_num; //边终点所在数组序号
_tag_edge_node_t* next_node; //下一条边
}edge_node_t;
//顶点结点
typedef struct _tag_head_node_t
{
vertex_t data; //结点数据
edge_node_t* first_edge; //第一条边
}head_node_t;
#define MAX_NUMBER 20 //图中最大结点数目
//图结构
typedef struct _tag_graph_t
{
head_node_t head_data[MAX_NUMBER]; //顶点数组
unsigned int head_node_count; //顶点数目
}graph_t;
void create_adjacency_list(graph_t* graph)
{
edge_node_t* p_edge = NULL;
if (graph == NULL)
return;
graph->head_node_count = 6;
for (unsigned int i = 0; i < graph->head_node_count; ++i)
{
graph->head_data[i].data = ‘A’ + i;
graph->head_data[i].first_edge = NULL;
}
graph->head_data[0].first_edge = new edge_node_t;
p_edge = graph->head_data[0].first_edge;
p_edge->node_num = 2;
p_edge->next_node = new edge_node_t;
p_edge = p_edge->next_node;
p_edge->node_num = 4;
p_edge->next_node = new edge_node_t;
p_edge = p_edge->next_node;
p_edge->node_num = 5;
p_edge->next_node = NULL;
graph->head_data[1].first_edge = new edge_node_t;
graph->head_data[1].first_edge->node_num = 2;
graph->head_data[1].first_edge->next_node = NULL;
graph->head_data[2].first_edge = new edge_node_t;
graph->head_data[2].first_edge->node_num = 3;
graph->head_data[2].first_edge->next_node = NULL;
graph->head_data[3].first_edge = new edge_node_t;
graph->head_data[3].first_edge->node_num = 5;
graph->head_data[3].first_edge->next_node = NULL;
graph->head_data[4].first_edge = new edge_node_t;
graph->head_data[4].first_edge->node_num = 1;
graph->head_data[4].first_edge->next_node =
new edge_node_t;
p_edge = graph->head_data[4].first_edge->next_node;
p_edge->node_num = 3;
p_edge->next_node = new edge_node_t;
p_edge = p_edge->next_node;
p_edge->node_num = 5;
p_edge->next_node = NULL;
}
void depth_first_search(graph_t* graph, int start_pos)
{
stack<int> visit_node;
bool is_visit[MAX_NUMBER]; //访问标志数组
for (int i = 0; i < MAX_NUMBER; ++i)
is_visit[i] = false;
cout<<graph->head_data[start_pos].data<<endl;
is_visit[start_pos] = true;
visit_node.push(start_pos); //将第一个元素压栈
while (!visit_node.empty())
{
int num = visit_node.top();
edge_node_t* next = graph->head_data[num].first_edge;
for (; next != NULL; next = next->next_node) //存在边，且该边的终点未被访问
{
if (!is_visit[next->node_num])
{
cout<<graph->head_data[next->node_num].data<<endl;
is_visit[next->node_num] = true;
visit_node.push(next->node_num);
break;
}
}
if (next == NULL) //以该结点为起点的所有终点访问完毕
visit_node.pop();
}
}
int main(int argc, char* argv[])
{
graph_t graph;
create_adjacency_list(&graph);
depth_first_search(&graph, 0);
return 0;
}
