Dijkstra_problem

#include <bits/stdc++.h>
#define inf 999999
using namespace std;
class Node
{
public:
    int parent,key,number;

    bool mst;

    vector< pair<int,int> > adj;

    bool operator<(const Node &obj)const
    {
        return key>obj.key;
    }


};

int main()
{
    int vertex,edges;
    cout<< "how many vertex and edges? ";
    cin>>vertex>>edges;
    Node node[vertex];

    for(int i=0; i<vertex; i++)
    {
        node[i].key=inf;
        node[i].mst=false;
        node[i].parent=-1;
        node[i].number=i;
    }

    vector<int> neg;
    for(int i=0; i<edges; i++)
    {
        int u,v,w;
        cin>>u>>v>>w;
        neg.push_back(w);

        node[u].adj.push_back(make_pair(v,w));
        node[v].adj.push_back(make_pair(u,w));

    }

    for(int i=0; i<neg.size(); i++)
    {
        if(neg[i]<0)
        {
            cout<< "Not possible. this algorithm can not handled negative edges"<<endl;
            return 0;
        }
    }
    int r;
    cout<< "Enter source vertex:";
    cin>>r;
    node[r].key=0;
    priority_queue<Node>pq;
    pq.push(node[r]);
    string s="";
    while(!pq.empty())
    {
        Node obj=pq.top();
        int u=obj.number;
        pq.pop();

        if(node[u].mst==false)
        {
            node[u].mst=true;


            cout<<"vertex: "<< node[u].number<< " Distance : "<< node[u].key<<endl;
            s+=" "+to_string(node[u].number);
            cout<< "Path: "<<s<<endl;


            for(int i=0; i<node[i].adj.size(); i++)
            {
                int v= node[u].adj[i].first;
                int w=node[u].adj[i].second;

                if(node[v].mst==false&&node[u].key+w<node[v].key)
                {
                    node[v].key=node[u].key+w;
                    node[v].parent=node[u].number;
                    pq.push(node[v]);
                }
            }
        }
    }

neg.clear();

    return 0;
}