Dijkstra

#include<bits/stdc++.h>
using namespace std;

void addEdge(vector<pair<int,int>> adj[], int u, int v, int w)
{
    adj[u].push_back({v,w});
    adj[v].push_back({u,w});
}
void dijkstra(vector<pair<int,int>> adj[], int V, int source)
{
    vector<int> dis(V,-1);
    vector<int> vis(V,0);
    priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> p;
    p.push({0,source});
    while(!p.empty())
    {
        pair<int,int> q=p.top();
        p.pop();
        int d=q.first;
        int vertex=q.second;
        if(vis[vertex]==1)
            continue;
        vis[vertex]=1;
        dis[vertex]=d;
        for(auto x:adj[vertex])
        {
            if(vis[x.first]==0)
                p.push({d+x.second,x.first});
        }
    }
    for(int i=0;i<V;i++)
        cout<<dis[i]<<" ";
}

void printGraph(vector<pair<int,int>> adj[], int V)
{
    for (int v = 0; v < V; ++v)
    {
        cout << "Adjacency list of vertex "
             << v << "\n";
        for (auto x : adj[v])
           cout << x.first <<" "<<x.second<<endl;
        cout<<"\n";
    }
}
int main()
{
    int V = 5;
    vector<pair<int,int>> adj[V];
    addEdge(adj,0, 1, 9);
    addEdge(adj,0, 3, 4);
    addEdge(adj,1, 3, 8);
    addEdge(adj,3, 2, 3);
    addEdge(adj,3, 4, 10);
    vector<int> vis(V,0);
    printGraph(adj,V);
    dijkstra(adj,V,4);
    return 0;
}