【源代码】C++算法（十）用邻接表实现图以及图拓扑排序

日常说明：首先博主也是菜鸟一枚，有错误欢迎大家指正。另外本博客所有的代码博主编写后均调试
通过。重要提醒！！！！博主使用的是VS2017，如果有低版本的小伙伴
最好新建空项目将此代码复制上去。
更多算法请关注我的算法专栏https://blog.csdn.net/column/details/20417.html
运行截图：

Toposort.h

#pragma once
#define Max 100
#include <iostream>
#include <cstdlib>
#include<stack>
typedef int indegree[Max];
using namespace std;

class ArcNode
{
public:
    int Vnum;
    int weight;
    ArcNode *arc_next;
    ArcNode()
    {
        this->arc_next = NULL;
    }
    ArcNode(int Vnum, ArcNode*arc_next = NULL)
    {
        this->arc_next = arc_next;
        this->Vnum = Vnum;
        this->weight = weight;
    }
};

typedef struct VNode
{
    char data;
    ArcNode *firstedge;
}VNode, AdjList[Max];


class ALGraph
{
public:
    ALGraph(indegree indeg);
    int TopologicalSort(ALGraph &graph, indegree indegree);
//private:
    int edge_num;
    int vexs_num;
    AdjList AdjList[Max];
};


 ALGraph::ALGraph(indegree indeg)
{

    this->vexs_num = 0;
    this->edge_num = 0;
    cout << "请输入顶点数和边数：";
    cin >> this->vexs_num >> this->edge_num;
    ArcNode *p,*q;
    cout << endl;
    cout << "请输入各顶点：";
    for (int i = 0; i < this->vexs_num; i++)
     {
         indeg[i] = 0;
     }
    for (int i = 0; i < this->vexs_num; i++)
    {
        cin >> this->AdjList[i]->data;
        this->AdjList[i]->firstedge = NULL;
    }
    cout << "请输入箭尾箭头顶点坐标以及相应的权值："<<endl;
    for (int i = 0; i < this->edge_num; i++)
    {
        int j, k, w;
        p = (ArcNode*)malloc(sizeof(ArcNode));
        cin >> j >> k >> w;
        ++indeg[k];
        p->Vnum = k;
        p->weight = w;
        p->arc_next = this->AdjList[j]->firstedge;
        this->AdjList[j]->firstedge = p;
    }

    cout << "顶点   出度表"<<endl;
    for (int i = 0; i < this->vexs_num; i++)
    {
        q = (ArcNode*)malloc(sizeof(ArcNode));
        q = this->AdjList[i]->firstedge;
        cout << this->AdjList[i]->data<<"       ";
        while (q != NULL)
        {
            int k;
            k = q->Vnum;
            cout <<AdjList[k]->data<<"   ";
            q = q->arc_next;
        }
        cout << endl;
    }

}

int ALGraph::TopologicalSort(ALGraph &graph, indegree indegree)
 {
     //若G无回路，则输出拓扑排序序列并返回1，若有回路返回0。
     ArcNode *q;
     int i, k;
     int gettop;
     stack<int>stack;
     int top = 0;
     for (i = 0; i < graph.vexs_num; i++)
     {
         if (0 == indegree[i])        //将入度为0的顶点入栈
         {
             stack.push(i);
         }
     }  
     int count = 0;
     while (!stack.empty())
     {
         gettop = stack.top();

         stack.pop();
         ++count;
         if (count<graph.vexs_num)
         {
             cout << graph.AdjList[gettop]->data << "-->"; //输出i号顶点，并计数
         }
         else
         {
             cout << graph.AdjList[gettop]->data;
         }
         for (q = graph.AdjList[gettop]->firstedge; q; q = q->arc_next)
         {
             k = q->Vnum;
             if (!(--indegree[k]))        //将i号顶点的邻接点的入度减1，如果减1后为0，则入栈
                 stack.push(k);
         }//for
     }//while
     cout << endl;
     if (count <= graph.vexs_num)  return 1;
     return 0;
 }

Toposort.cpp

#include"Toposort.h"



int main()
{
    indegree inde;
    ALGraph graph(inde);
    cout << endl;
    cout << "拓扑排序结果为：" << endl;
    graph.TopologicalSort(graph,inde);
    return 0;
}