single source shortest path using stl in c++

dijkstras.cpp

#include<bits/stdc++.h>
#define INF 0x3f3f3f3f
#define V 4
using namespace std;

list< pair<int,int> > adj[V];

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

void shortestpath(int src)
{

    set< pair<int,int> > setds;
    vector<int> dist(V,INF);

    setds.insert(make_pair(0,src));
    dist[src]=0;
    while(!setds.empty())
    {

        pair<int,int> temp= *(setds.begin());
        setds.erase(setds.begin());

        int u=temp.second;

        list<pair<int,int> >::iterator i;

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

            int v=(*i).first;//vertex adjacent to u
            int w=(*i).second;//weight of edge u--->v

            if(dist[v]>dist[u]+w)
            {
                //IF THE VERTEX "V" IS ALREADY IN OUR SET THEN FIRST ERASE THEN INSERT AGAIN AFTER UPADTING DISTANCE
                if(dist[v]!=INF)
                    setds.erase(setds.find(make_pair(dist[v],v)));

                dist[v]=dist[u]+w;
                setds.insert(make_pair(dist[v],v));
            }
        }
    }

    for(int i=0;i<V;i++)
        cout<<dist[i]<<" ";
}
int main()
{

    addedge(0,1,1);
    addedge(1,3,2);
    addedge(3,2,3);
    addedge(0,2,8);
    addedge(0,3,5);

    shortestpath(0);
}