Minimum Spanning Tree (Prims Algorithm)

/***
    Minimum Spanning Tree (Prims Algorithm)
    Author : Md.Saiful Islam
***/
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <queue>


using namespace std;


#define SIZE 10000


struct pq
{
int cost,node;
bool operator<(const pq &b)const
{
return cost>b.cost;    // Min Priority Queue
}
};


int Prims(vector<pq>adj[],int source,int nodes)
{
priority_queue<pq>Q;
vector<int>color(nodes);
pq U,V;
int i,sum;


V.node=source;
sum=V.cost=0;
Q.push(V);
while(!Q.empty())
{
U=Q.top();
if(color[U.node]==0)
            sum+=U.cost;
color[U.node]=1;
Q.pop();
for(i=0;i<adj[U.node].size();i++)
{
if(color[ adj[U.node][i].node]==0)
{
V.node=adj[U.node][i].node;
V.cost=adj[U.node][i].cost;
Q.push(V);
}
}
}
return sum;
}


int main()
{
int nodes,edges,i,u,v,cost,source,val;
pq V;
vector<int>dist;
vector<pq>adj[SIZE];


while(scanf("%d %d",&nodes,&edges)==2)
{
for(i=0;i<nodes;i++)
{
adj[i].clear(); //clear adj vector
}
for(i=0;i<edges;i++)
{
scanf("%d %d %d",&u,&v,&cost);
V.cost=cost;
V.node=v;
adj[u].push_back(V);
V.node=u; //For Bidirectional Edges
adj[v].push_back(V);
}
val=Prims(adj,0,nodes);
printf("%d\n",val);
}


return 0;
}
/*
    Input:
    5 7
    0 1 5
    0 2 4
    1 2 2
    1 4 3
    2 4 1
    2 3 4
    3 4 3
    Output:
    10
*/