Cod sursa(job #2315779)

Utilizator rexlcdTenea Mihai rexlcd Data 10 ianuarie 2019 15:52:53
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.2 kb
#include <iostream>
#include <fstream>
#include <set>
#include <vector>
#include <cstring>

using namespace std;

const int INF = 0x3f3f3f3f;
const int N_MAX = 50002;

set < pair < int , int > > s;
vector < pair < int , int > > v[N_MAX];

int d[N_MAX];

int main()
{
    ifstream f("dijkstra.in");
    ofstream g("dijkstra.out");
    int n, m; f >> n >> m;
    for(int i = 1, x, y, c; i <= m; i++)
    {
        f >> x >> y >> c;
        v[x].push_back({y, c});
    }

    memset(d, INF, sizeof(d));
    d[1] = 0;
    for(int i = 1; i <= n; i++)
        s.insert({d[i], i});

    while(!s.empty())
    {
        int cost = (*s.begin()).first, x = (*s.begin()).second;
        s.erase({cost, x});

        for(int i = 0; i < v[x].size(); i++)
        {
            int y = v[x][i].first, c = v[x][i].second;

            if(d[x] + c < d[y])
            {
                s.erase({d[y], y});

                d[y] = d[x] + c;
                s.insert({d[y], y});
            }
        }
    }

    for(int i = 2; i <= n; i++)
    {
        if(d[i] == INF)
            d[i] = 0;
        g << d[i] << " ";
    }
    g << '\n';
    f.close();
    g.close();
    return 0;
}