Dijkstra + Bellman ( Adj List + Priority Queue )

#include<bits/stdc++.h>
using namespace std;
# define INF 0x3f3f3f3f

typedef pair<int, int> PAIR;

class Edge
{
    int V;
    int u,v,w;
    list<PAIR> *adj;

public:
    Edge(int V)
    {
        this->V = V;
        adj = new list<PAIR> [V];

    }
    int getVerticesNumber()
    {
        return V;
    }
    int getWeight()
    {
        return w;
    }

    void setEdge(int u,int v,int w)
    {
        adj[u].push_back(make_pair(v,w));
    }

};


class Graph
{
    int V,m;

    list< pair<int, int> > *adj;

public:
    Graph(int V,int m);


    void addEdge(int u, int v, int w);


    void Dijkstra(int s);
    bool Bellman(int s);
};

Graph::Graph(int V,int m)
{
    this->V = V;
    this->m = m;
    adj = new list<PAIR> [V];
}

void Graph::addEdge(int u, int v, int w)
{

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


void Graph::Dijkstra(int src)
{

    priority_queue< PAIR, vector <PAIR>, greater<PAIR> > pq;
    vector<int> dist(V, INF);

    pq.push(make_pair(0, src));
    dist[src] = 0;

    while (!pq.empty())
    {

        int u = pq.top().second;
        pq.pop();

        for (auto i = adj[u].begin(); i != adj[u].end(); ++i)
        {

            int v = (*i).first;
            int weight = (*i).second;

            if (dist[v] > dist[u] + weight)
            {

                dist[v] = dist[u] + weight;
                pq.push(make_pair(dist[v], v));
            }
        }
    }

    printf("Vertex Distance from Source\n");
    for (int i = 0; i < V; ++i)
        printf("%d \t\t %d\n", i, dist[i]);
}

bool Graph::Bellman(int src)
{
    bool negative_edge = false;
    vector<int> dist(V, INF);
    dist[src] = 0;

    for(int i = 0; i<V-1; i++)
    {
        for(int u = 0; u<V;u++)
        {
            for(auto j = adj[u].begin();j!=adj[u].end();j++)
            {
                int v = (*j).first;
                int w = (*j).second;

                if(dist[u]!=INF && dist[v] > dist[u] + w)
                {
                    dist[v] = dist[u] + w;
                }
            }
        }
    }

    for(int u = 0; u<V;u++)
        {
            for(auto j = adj[u].begin();j!=adj[u].end();j++)
            {
                int v = (*j).first;
                int w = (*j).second;

                if(dist[u]!=INF && dist[v] > dist[u] + w)
                {
                    negative_edge = true;
                    return negative_edge;
                }
            }
        }

        return negative_edge;

}

int main()
{

    int V = 9;
    int m = 14;
    Graph g(V,m);
    g.addEdge(0, 1, 4);
    g.addEdge(0, 7, 8);
    g.addEdge(1, 2, 8);
    g.addEdge(1, 7, 11);
    g.addEdge(2, 3, 7);
    g.addEdge(2, 8, 2);
    g.addEdge(2, 5, 4);
    g.addEdge(3, 4, 9);
    g.addEdge(3, 5, 14);
    g.addEdge(4, 5, 10);
    g.addEdge(5, 6, 2);
    g.addEdge(6, 7, 1);
    g.addEdge(6, 8, 6);
    g.addEdge(7, 8, 7);

    g.Dijkstra(0);
    g.Bellman(0);

    return 0;
}