所有节点最短路径的Johnson实现

一、数据集形式

二、数据集

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 <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"
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() {
weight = 65535;
smallWeigth = NULL;
}
~CTree() {}
int value;
CTreeNode *next;
CTree *before;
double weight;

CWeightSort *smallWeigth;
bool state;
};
CTree * S;
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];
S = new CTree;
S->weight = 0;
S->value = 0;
S->next = NULL;
S->before = NULL;
CTreeNode *nt;
//为树赋初值
for (int i = 0; i < nodeNumber; i++)
{
nt = new CTreeNode;
nt->value = i;
nt->weight = 0;
nt->next = S->next;
S->next = nt;

tree[i].next = NULL;
tree[i].value = i;
tree[i].before = NULL;
}
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;
}
//Bellman算法
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 *S,CTree *tree)
{
myQ.push(S);
while (!myQ.empty())
{
Bellman(myQ.front(), tree);
myQ.pop();
}
}
double **Johnson;
//Dijkstra 算法
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;
};
void initDijkstra(CTree *tree, int in)
{
for (int i = 0; i < nodeNumber; i++)
{
tree[i].state=true;
tree[i].before = NULL;
//delete tree[i].smallWeigth;
tree[i].smallWeigth = NULL;
}
tree[in].smallWeigth = new CWeigh
4000
tSort;
tree[in].smallWeigth->weight = 0;
}
CTree* Dijkstra(CTree *tree,int in)
{
initDijkstra(tree, in);
CQueue myQue;
CWeightSort *myi = new CWeightSort;
myi->value = in;
myi->before = NULL;
myQue.Add(myi);
CWeightSort *nt = NULL;
while (!myQue.empty())
{
nt = myQue.del(myQue.que->next);
Johnson[in][nt->value] = nt->weight + tree[nt->value].weight - tree[in].weight;//如果在这里设置数组可以得到所有值，但占用空间太大
//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();
//修改图中的weight
Bell(S,tree);
//对图边的权重进行改变
for (int i = 0; i < nodeNumber; i++)
{
CTreeNode *p = tree[i].next;
while (p!=NULL)
{
p->weight = p->weight + tree[0].weight - tree[p->value].weight;
p = p->next;
}
}
//对于每个节点进行Dijkstra

Johnson = new double *[nodeNumber];
for (int i = 0; i < nodeNumber ; i++)
{
Johnson[i] = new double[nodeNumber];
memset(Johnson[i], 65535, sizeof(double)*nodeNumber);
}
for (int i = 0; i < nodeNumber; i++)
{
CTree *q = Dijkstra(tree, i);

}

finish = clock();
useTime = (double)(finish - start) / CLOCKS_PER_SEC * 1000;
printf("%f 毫秒\n", useTime);
system("pause");
return 0;
}