Dijk

#include<iostream>
using namespace std;
#define infi 999
class queue
{
private:
    int q[100];
    int front, rear;
	protected:
    queue()
    {
        front = rear = -1;
    }
    int isempty()
    {
        if ((front == -1 && rear == -1) || (front > rear))
        {
            front = rear = -1;
            return 1;
        }
        return 0;
    }
    void push(int a)
    {
        if (isempty())
            front++;
        q[++rear] = a;
	    };
    int del()
    {
        return q[front++];
    }
};
class dj : public queue
{
private:
   int mat[20][20], dist[20], path[20];
public:
    int n;
    void input()
    {
        cout << "Enter number of nodes:\n";
        cin >> n;
        cout << "\n\nEnter adjacency matrix\n" << endl;
        for (int i = 1;i <= n;i++)
        {
            cout << " enter the weights of row " << i <<" : ";
            for (int j = 1;j <= n;j++)
                cin >> mat[i][j];
        }
    }
    void init(int m)
    {
        push(m);
	        dist[m] = 0;
        for (int i = 1;i <= n;i++)
	        {
            if (i != m)
	            {
                push(i);
	                dist[i] = infi;
            }
            path[i] = 0;
        }
    }
    void min_dist(int m)
    {
        int v, w;
        init(m);
        while (!(isempty()))
        {
            v = del();
            cout << "this is v del " <<v <<endl;
            for (int i = 1;i <= n;i++)
            {
                if (mat[v][i] != 0)
                {
                    w = i;
                    if ((dist[v] + mat[v][w]) < (dist[w]))
                 {
	                        dist[w] = dist[v] + mat[v][w];
                       path[w] = v;
 
                    }
                }
            }
        }
    }
    void disp_path(int m)
    {
        int p = path[m];
        if (p == 0)
            return;
        disp_path(p);
        cout << " " << m;
    }
    void disp_dist(int m)
    {
        cout << "Cost: " << dist[m] << endl << endl;
    }
};
int main()
{
    int startnode,endnode;
    char answer;
    dj a;
    a.input();
    do
    {
        cout << "start node: ";
        cin >> startnode;
        cout << "end node: ";
        cin >> endnode;
        a.min_dist(startnode);
        cout<<"\nFrom "<<startnode<<" to "<<endnode<<":"<<endl;
        cout<<"------------"<<endl;
        cout<<"Minimum distance route: ("<<startnode;
        a.disp_path(endnode);
        cout<<")"<<endl;
        a.disp_dist(endnode);
        cout << "Do you want to calculate another path (Y/N)? ";
        cin >> answer;
    } while (answer != 'n');
 
}