#include <iostream>
#include <string>
#include <queue>
using namespace std;
typedef struct Edgenode
{
int adjvex;
struct Edgenode *next;
}Edgenode;
typedef struct Vertexnode
{
string data;
Edgenode *firstedge;
}Vertexnode,Adjlist[10];
typedef struct Graph
{
Adjlist vertex_node;
int num_vertex;
int num_edge;
}Graph;
int get_location(Graph g, string s)
{
int i;
for(i=0;i<g.num_vertex;i++)
{
if(s == g.vertex_node[i].data)
return i;
}
return -1;
}
void create_graph(Graph &g)//建立有向圖
{
int i,j,k;
string s1,s2;
cout<<"請輸入頂點數和邊數:";
cin>>g.num_vertex>>g.num_edge;
cout<<"請輸入頂點:";
for(i=0;i<g.num_vertex;i++)
{
cin>>g.vertex_node[i].data;
g.vertex_node[i].firstedge = NULL;
}
cout<<"請輸入邊:"<<endl;
for(k=0;k<g.num_edge;k++)
{
cin>>s1>>s2;
i = get_location(g,s1);
j = get_location(g,s2);
Edgenode *p = new Edgenode();
p->adjvex = j;
p->next = g.vertex_node[i].firstedge;
g.vertex_node[i].firstedge = p;
}
}
void print_graph(Graph g)//列印鄰接表
{
cout<<"鄰接表如下:"<<endl;
int i;
for(i=0;i<g.num_vertex;i++)
{
cout<<g.vertex_node[i].data;
Edgenode *p = g.vertex_node[i].firstedge;
while(p)
{
cout<<"->"<<g.vertex_node[p->adjvex].data;
p = p->next;
}
cout<<endl;
}
}
void find_indegree(Graph g, int indegree[])//計算每個頂點的入度
{
int i;
for(i=0;i<g.num_vertex;i++)
indegree[i]=0;
for(i=0;i<g.num_vertex;i++)
{
Edgenode *p = g.vertex_node[i].firstedge;
while(p)
{
indegree[p->adjvex]++;
p=p->next;
}
}
}
void topologicalsort(Graph g)//拓撲排序
{
int indegree[10];//入度
int count = 0;//計數
find_indegree(g,indegree);
int i;
queue<int> q;
for(i=0;i<g.num_vertex;i++)//把度為0的頂點入隊
{
if(indegree[i]==0)
q.push(i);
}
while(!q.empty())
{
int k = q.front();
q.pop();
cout<<g.vertex_node[k].data<<" ";
count++;
Edgenode *p = g.vertex_node[k].firstedge;
while(p)
{
if(--indegree[p->adjvex]==0)//将度為0的頂點的鄰接頂點入度減1，如果變為0則将其入隊
q.push(p->adjvex);
p=p->next;
}
}
cout<<endl;
if(count != g.num_vertex)//如果最終計數值和頂點數不相等，說明有的頂點入度沒有變為0，存在環路
cout<<"有向圖存在環路!"<<endl;
}
int main()
{
Graph g;
create_graph(g);
print_graph(g);
cout<<"拓撲排序:"<<endl;
topologicalsort(g);
return 0;
}
測試用例一：
測試用例二：