Cod sursa(job #3212943)

Utilizator TaniaKallosKallos Tania TaniaKallos Data 12 martie 2024 12:28:17
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.51 kb
#include <fstream>
//#include <iostream>
#include <vector>
#include <set>

using namespace std;

//
ifstream cin("dijkstra.in");
ofstream cout("dijkstra.out");
//


const int N = 5e4;
const long long INF = 2e9;
int n, m;
long long d[N+1];
bool viz[N+1];
vector < pair<int, int> > g[N+1];
set < pair<long long, int> > costs;


void dijkstra(int rad)
{
    for (int i = 1; i <= n; i++)
        d[i] = INF;
    
    d[rad] = 0;
    costs.insert( make_pair(0, rad) );

    while (!costs.empty())
    {
        //int dist = costs.begin()->first;
        int node = costs.begin()->second;
        costs.erase( costs.begin() );

        if (viz[node])
            continue;
        viz[node] = 1;

        for (int i = 0; i < g[node].size(); i++)
        {
            int vec = g[node][i].first;
            long long cost = 1ll * g[node][i].second;
            if (!viz[vec] && d[vec] > d[node] + cost)
            {
                if (d[vec] < INF)
                    costs.erase( costs.find( make_pair(d[vec], vec) ) );
                d[vec] = d[node] + cost;
                costs.insert( make_pair(d[vec], vec) );
            }
        }
    }
}


int main()
{
    cin >> n >> m;

    for (int i = 1; i <= m; i++)
    {
        int a, b, c;
        cin >> a >> b >> c;
        g[a].push_back( make_pair(b, c) );
        g[b].push_back( make_pair(a, c) );
    }


    dijkstra(1);

    for (int i = 2; i <= n; i++)
    {
        if (d[i] < INF)
            cout << d[i] << ' ';
        else
            cout << 0 << ' ';
    }


    return 0;
}