Prims Code

#include<iostream>
#include<queue>
#include<string.h>

using namespace std;


int n,e,edge[100][100];

struct node
{
    int cost, vertex;
};

bool operator<(node a, node b)
{
    return a.cost>b.cost;
}
int prims()
{
    bool visited[100];

    memset(visited, false, sizeof(visited));
    node temp;

    temp.cost=0;
    temp.vertex=0;

    priority_queue<node>pq;
    pq.push(temp);

    int ans=0;

    while(!pq.empty())
    {
        node cur = pq.top();
        pq.pop();

        if(visited[cur.vertex])
        {
            continue;
        }
        visited[cur.vertex] = true;
        ans=ans+cur.cost;


        for(int i=0; i<n; i++)
        {
            if(edge[cur.vertex][i] >=0)
            {
                node t;
                t.cost=edge[cur.vertex][i];
                t.vertex=i;


                if(visited[i] == false)
                {
                    pq.push(t);
                }
            }
        }
    }
    return ans;
}

int main()
{
    while(cin>>n>>e)
    {
        for(int i=0; i<n; i++)
        {
            for(int j=0; j<n; j++)
            {
                edge[i][j]=-1;;
            }
        }
        for(int i=0; i<e; i++)
        {
            int a,b,c;
            cin>>a>>b>>c;

            edge[a][b]=c;
            edge[b][a]=c;
        }
        int ans = prims();
        cout<<ans<<endl;
    }

    return 0;
}