单源点最短路径Bellman算法实现

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

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

#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"
class CTreeNode
{
public:
    CTreeNode()
    {}
    ~CTreeNode() {}
    int value;
    double  weight;
    CTreeNode *next;
};
class CTree
{
public:
    CTree() {
        weight = 65535;
    }
    ~CTree() {}
    int value;
    CTreeNode *next;
    CTree *before;
    double weight;
};
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].before = NULL;
    }
    tree[0].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;
}
queue<CTree *> myQ;
void Bellman(CTree *t, CTree *tree)
{
    CTreeNode *p = t->next;
    while (p!=NULL)
    {
        //链接的节点已经完成，不做任何改变
        if (t->weight!=65535&&tree[p->value].weight>t->weight+p->weight)
        {
            //cout << tree[p->value].value << " ";
            tree[p->value].weight = t->weight + p->weight;
            tree[p->value].before = t;
            //Bellman(tree, p->value);
            myQ.push(&tree[p->value]);
        }
        p = p->next;
    }
}
void Bell(CTree *tree)
{
    myQ.push(&tree[0]);
    while (!myQ.empty())
    {
        Bellman(myQ.front(),tree);
        myQ.pop();
    }
}
int main()
{
    //构建图
    CTree *tree = createTree(PATH);
    double useTime;
    clock_t start, finish;
    start = clock();
    //算法
    Bell(tree);
    finish = clock();
    useTime = (double)(finish - start) / CLOCKS_PER_SEC * 1000;
    printf("%f 毫秒\n", useTime);
    system("pause");
    return 0;
}