单源点最短路径Dijkstra方法实现

一、数据集形式

其中：6105（节点个数） 7035（边数）
0（id） 1609（起始边） 1622（终边） 57.403187（权重）

二、数据集

数据集下载链接

三、实现代码

// Dijkstra.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "time.h"
#include <fstream>
#include<iostream>
#include <stack>
#include<algorithm>
using namespace std;

//#define PATH "E://dataset//MapSet//MinCreateTree//Testnew.txt"

//#define PATH "E://dataset//MapSet//MinCreateTree//Ol.txt"
//#define PATH "E://dataset//MapSet//MinCreateTree//TGRoad.txt"
//#define PATH "E://dataset//MapSet//MinCreateTree//California.txt"
//#define PATH "E://dataset//MapSet//MinCreateTree//San.txt"
//#define PATH "E://dataset//MapSet//MinCreateTree//NA.txt"
int nodeNumber;
int edgeNumber;
class CWeightSort {
public:
    int value;
    double weight;
    CWeightSort *before;
    CWeightSort *next;
};
class CTreeNode
{
public:
    CTreeNode()
    {}
    ~CTreeNode() {}
    int value;
    double  weight;
    CTreeNode *next;
};
class CTree
{
public:
    CTree() {
        smallWeigth = NULL;
    }
    ~CTree() {}
    int value;
    CTreeNode *next;
    CTree *before;
    CWeightSort *smallWeigth;
    bool state;
};
CTree* createTree(char* filename)
{
    CTree *tree;
    ifstream ReadFile;
    int temp;
    ReadFile.open(filename, ios::in);//ios::in 表示以只读的方式读取文件
    ReadFile >> nodeNumber;//第一个字符是数组长度
    ReadFile >> edgeNumber;
    tree = new CTree[nodeNumber];
    //为树赋初值
    for (int i = 0; i < nodeNumber; i++)
    {
        tree[i].next = NULL;
        tree[i].value = i;
        tree[i].state = true;
        tree[i].before = NULL;
    }
    tree[0].smallWeigth = new CWeightSort;
    tree[0].smallWeigth->weight = 0;
    CTreeNode *nt;
    while (!ReadFile.eof())            //按空格读取，遇到空白符结束
    {
        nt = new CTreeNode();       //读出的数据新建一个节点
        ReadFile >> temp;
        ReadFile >> temp;
        ReadFile >> (nt->value);
        ReadFile >> (nt->weight);
        nt->next = tree[temp].next;
        tree[temp].next = nt;
    }
    return tree;
}

class CQueue {                                  //一个保持队形的队列结构
public:
    CQueue() {
        que = new CWeightSort();
        que->next = NULL;
    }
    void Add(CWeightSort *nq) {
        //将新节点按顺序插入到队列上
        CWeightSort *q = que;
        while (q->next != NULL)
        {
            if (nq->weight < q->next->weight)
            {
                q->next->before = nq;
                nq->next = q->next;
                nq->before = q;
                q->next = nq;
                break;
            }
            q = q->next;
        }
        if (q->next == NULL)
        {
            nq->next = q->next;
            nq->before = q;
            q->next = nq;
        }
    }
    CWeightSort * del(CWeightSort *nq)
    {
        nq->before->next = nq->next;
        if (nq->next != NULL)
            nq->next->before = nq->before;
        return nq;
    }
    bool empty()
    {
        if (que->next == NULL)
            return true;
        return false;
    }
    CWeightSort *que;
};
CTree* Dijkstra(CTree *tree)
{
    CQueue myQue;
    CWeightSort *myi=new CWeightSort;
    myi->value = 0;
    myi->before = NULL;
    myQue.Add(myi);
    CWeightSort *nt=NULL;
    while (!myQue.empty())
    {
        nt = myQue.del(myQue.que->next);
        //cout << nt->value << "(" << nt->weight << ")" << " ";
        //标记这个节点为已经访问状态
        tree[nt->value].state = false;
        CTreeNode *p = tree[nt->value].next;
        while (p!=NULL)
        {
            //链接的节点已经完成，不做任何改变
            if (tree[p->value].state)
            {
                //链接的节点，没有更小的值
                if (tree[p->value].smallWeigth == NULL)
                {
                    CWeightSort *node = new CWeightSort;
                    node->value = p->value;
                    node->weight = tree[nt->value].smallWeigth->weight + p->weight;
                    tree[p->value].smallWeigth = node;
                    tree[p->value].before = &tree[nt->value];
                    myQue.Add(node);
                }
                //链接的节点，存在更小的值
                else if (tree[p->value].smallWeigth->weight>tree[nt->value].smallWeigth->weight+p->weight)
                {
                    CWeightSort *node=myQue.del(tree[p->value].smallWeigth);
                    node->value = p->value;
                    node->weight = tree[nt->value].smallWeigth->weight + p->weight;
                    tree[p->value].smallWeigth = node;
                    tree[p->value].before = &tree[nt->value];
                    myQue.Add(node);
                }
            }

            p = p->next;
        }

    }
    return &tree[nt->value];
}
int main()
{
    //构建图
    CTree *tree = createTree(PATH);
    double useTime;
    clock_t start, finish;
    start = clock();
    //算法
    CTree* m=Dijkstra(tree);
    finish = clock();
    useTime = (double)(finish - start) / CLOCKS_PER_SEC * 1000;
    printf("%f 毫秒\n", useTime);
    system("pause");
    return 0;
}