单源点最短路径Dijkstra方法实现

本文主要是介绍单源点最短路径Dijkstra方法实现，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

一、数据集形式

这里写图片描述
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;
}