【源代码】严蔚敏数据结构算法C++（十九）多段图

日常说明：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
有朋友反映让我多加备注，我觉得除非特别惊艳的方法需要说明外，这些基本的方法是容易明白的，当然前提是先搞懂算法的基本思想，希望对你们有用。

运行结果：

Mulgraph.h

#pragma once
#define Max 100
#include <iostream>
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
{
    int data;
    ArcNode *firstedge;
}VNode, AdjList[Max];

class ALGraph
{
public:
    ALGraph();
    void mulgraph(ALGraph&);
    int edge_num;
    int vexs_num;
    AdjList AdjList[Max];
};

Mulgraph.cpp

#include"MulGraph.h"

ALGraph::ALGraph()
{
    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++)
    {
        cin >> this->AdjList[i]->data;
        this->AdjList[i]->firstedge = NULL;
    }
    cout << endl;
    cout << "请输入顶点以及相应的权值：" << endl;
    for (int i = 0; i < this->edge_num; i++)
    {
        int j, k, w;
        p = (ArcNode*)malloc(sizeof(ArcNode));
        cin >> j >> k >> w;
        p->Vnum = k;
        p->weight = w;
        p->arc_next = this->AdjList[j-1]->firstedge;
        this->AdjList[j-1]->firstedge = p;
    }
    cout << endl;
}

void ALGraph::mulgraph(ALGraph&graph)
{
    int *cost = new int[graph.vexs_num];
    int *path = new int[graph.vexs_num];
    for (int i = 0; i < graph.vexs_num; i++)
    {
        cost[i] = Max;
        path[i] = 0;
    }
    cost[graph.vexs_num - 1] = 0;
    ArcNode *head;
    for (int i = graph.vexs_num-1; i >=0; i--)
    {
        head = graph.AdjList[i]->firstedge;
        while (head!=NULL)
        {
            if (cost[head->Vnum-1]+head->weight < cost[i])
            {
                cost[i] = cost[head->Vnum-1] + head->weight;
                path[i+1] = head->Vnum;
            }
            head = head->arc_next;
        }
    }
    int mincost;
    mincost = cost[0];
    int j=1;
    while (path[j]!=NULL&&j<graph.vexs_num)
    {
        cout << path[j]<<" ";
        j = path[j];
    }
    cout << endl;
    free(path);
    free(cost);
    cout << endl;
    cout << "最短路径的总代价为："<<mincost;
    cout << endl;
}
int main()
{
    ALGraph graph;
    cout << "最短路径为:"<<graph.AdjList[0]->data<<" ";
    graph.mulgraph(graph);
    return 0;
}