Uva 721 - Invitation Cards

Problem Statement: 721 - Invitation Cards


/**
  *  @Author: Pranta Sarker
  *
  **/


// Algo: Dijkstra

#include<bits/stdc++.h>

using namespace std;

#define fast ios_base::sync_with_stdio(0)
#define bfast cin.tie(0)
#define outs(x) cout << x << " "
#define outn(x) cout << x << "\n"
#define sf scanf
#define pf printf
#define pfn(x , k) printf(k , x)
#define nl puts("")
#define psb push_back
#define mset(c,v) memset(c , v , sizeof c)
#define loop0(n) for(int i=0; i<n; i++)
#define loop1(n) for(int i=1; i<=n; i++)
#define mpair(x , y) make_pair(x , y)
#define all(x) x.begin(), x.end()
#define pi acos(-1.0)
#define psb push_back
#define clr clear()

typedef unsigned long long ull;
typedef long long LL;
typedef vector<int>vii;
typedef vector<LL>vll;
typedef vector<string>vs;
typedef map<int, int>mpii;
typedef map<string, int>mpsi;
typedef map<char, int>mpci;
typedef map<LL, LL>mpll;

const int mod = 1000007;
const LL high = 1e6+5;

LL minimum_cost = 0 , dis[high], visited[high];

struct data
{
    int node, cost;
    data(){ }
    data(int n , int c)
    {
        node = n;
        cost = c;
    }

bool operator<(const data &b) const
    {
        return cost > b.cost;
    }
};

vector<data>adj[high] , back_adj[high];

void CLR(int n)
{
    for(int i=1; i<=n; i++)
    {
        adj[i].clr;
        back_adj[i].clr;
        visited[i] = 0;
    }
}

void Dijkstra(int s, int n, vector<data>adj[])
{
    LL i=0 , j=0 , u=0 , v = 0 , w = 0, cost = 0;

    for(i=1; i<=n; i++) dis[i] = 1e15;

    dis[s] = 0;

    priority_queue<data>Q;

    Q.push(data(s , 0));

    while(!Q.empty())
    {
        u = Q.top().node;
        w = Q.top().cost;

        //cout << "u = " << u << " w = " << w << "\n";

        Q.pop();

        visited[u] = 0;

        for(i=0; i<adj[u].size(); i++)
        {
            v = adj[u][i].node;
            //cout << "V = " << v << "; ";

            int tm = dis[u];

            //cout << "tm = " << tm << "\n";

            //cost = adj[u][i].cost + w; // not the current state weight

            //cout << "1.cost = " << cost << "\n";


            cost = adj[u][i].cost + tm; // take always minimum state weight for each u

            //cout << "2.cost = " << cost << "\n";

            if(dis[v] > cost)
            {
                dis[v] = cost;

                //cout << "\ndis[" << v << "] = " << dis[v] << "\n";

                if(!visited[v])
                {
                    Q.push(data(v , cost));
                    visited[v] = 1;
                }
            }
        }
    }

    for(i=1; i<=n; i++)
    {
        minimum_cost += dis[i];
    }
}

int main()
{
    fast;
    int N;
    cin >> N;
    while(N--)
    {
        minimum_cost = 0;

        int u , v , w , i , P , Q;
        cin >> P >> Q;

        CLR(P);

        for(i=0; i<Q; i++)
        {
            cin >> u >> v >> w;

            adj[u].psb(data(v , w));

            back_adj[v].psb(data(u , w));
        }

        Dijkstra(1, P, adj);
        //cout << "2.\n";
        Dijkstra(1, P, back_adj);

        cout << minimum_cost << "\n";
    }

    return 0;
}