Dijkstra算法 用C++面向对象写

这个是我在coursera.org上学习 C++ For C Programmers 课程的一个作业。用C++面向对象来写算法，这增加了我对面向对象的理解。

方法为：

1、创建一个class类

2、定义私有数据成员

3、定义各种方法来对私有数据进行操作

代码如下：

#include <iostream>
#include <queue>

#define maxx 999999     //dustance infinity

using namespace std;

class Node
{
public:
    void Initialize();
    void deletemessage();
    void InputNodenum(int num);     //input node's number
    void InputMess(int i, int j, int distance);   //input i to j distance
    int Dijkstra(int star, int endnode);         //Dijkstra algorithm
private:
    int nodenum;            //node's quantity
    int digraph[200][200];  //'maxx' con't
    int min_distance[200];  //The shortest distance
    int sign[200];          //Whether to enter the queue,'0' is no, '1' is yes
    int distance;      //star to now's distance
};

void Node::Initialize()
{
    int i,j;
    for(i = 0; i < 200; i++)
    {
        sign[i] = 0;         //all node not enter the queue
        min_distance[i] = maxx;   //the distance that star to all node is 'maxx'
        for(j = 0; j < 200; j++)
        {
            digraph[i][j] = maxx;
        }
    }
    return ;
}

void Node::deletemessage()
{
    int i;
    for(i = 0; i < nodenum; i++)
    {
        sign[i] = 0;
        min_distance[i] = maxx;
    }
}

void Node::InputNodenum(int num)
{
    nodenum = num;
    return ;
}

void Node::InputMess(int i, int j, int distance)
{
    digraph[i][j] = distance;  //input distance
    digraph[j][i] = distance;
    return ;
}

int Node::Dijkstra(int star, int endnode)
{
    int now;           //now node
    int next;          //next node
    int newdis;        //new distance
    queue<int> q;
    q.push(star);      //star enter the queue
    min_distance[star] = 0;  //update star's distance
    while(!q.empty())  //this is BFS(Breadth First Search)
    {
        now = q.front();
        q.pop();
        sign[now] = 1; //sign 'now' is enter the queue
        for(next = 0; next < nodenum; next++)
        {
            if(digraph[now][next]!=maxx && sign[next] == 0)  //if now to next is link and next not enter queue, then next need enqueue
            {
                q.push(next);
                newdis = min_distance[now] + digraph[now][next];   //compute star to next node's distance
                if(newdis < min_distance[next])  //update next node's min_distance
                {
                    min_distance[next] = newdis;
                }
            }
        }
    }

    return min_distance[endnode];
}

int main()
{
    int a,b,distance,num;
    int pathnum;      //the path of number
    int star,endnode;
    int min_distance;
    Node *node= new Node();
    node->Initialize();
    cout<<"please input node's number(no more than 200) and the number of path:"<<endl;
    cout<<"node's number: ";
    cin>>num;
    cout<<"path's number: ";
    cin>>pathnum;
    node->InputNodenum(num);
    cout<<"please input node's information(a b distance) node's number is 0 to num-1"<<endl;
    for(int i = 0; i < pathnum; i++)
    {
        cin>>a>>b>>distance;
        node->InputMess(a,b,distance);
    }
    cout<<"please input star and end(end of EOF):"<<endl;
    while(cin>>star>>endnode)
    {
        node->deletemessage();
        min_distance = node->Dijkstra(star,endnode);
        if(min_distance == maxx)
        {
            cout<<"no path"<<endl;
        }
        else
        {
            cout<<"the short distance is: "<<min_distance<<endl;
        }
    }


    return 0;
}