Cod sursa(job #2076658)

Utilizator valentinoMoldovan Rares valentino Data 26 noiembrie 2017 21:38:44
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.39 kb
#include <iostream>
#include <set>
#include <vector>
#include <queue>
#include <fstream>
#include <algorithm>
#define NMax 50005
#define inf 0x3f3f3f3f
using namespace std;

ifstream f("dijkstra.in");
ofstream g("dijkstra.out");

int n, m, d[NMax];
vector < pair < int, int > > graf[NMax];
multiset < pair < int, int > > q;

int main()
{
    int x, y, c, nod, nod2, cost;
    vector < pair < int, int > > :: iterator it;
    multiset < pair < int, int > > :: iterator it2;
    f >> n >> m;
    q.insert({0, 1});
    for(int i = 2; i <= n; ++i)
    {
        d[i] = inf;
        q.insert({d[i], i});
    }
    for(int i = 1; i <= m; ++i)
    {
        f >> x >> y >> c;
        graf[x].push_back({y, c});
    }
    for(int i = 1; i <= n; ++i)
    {
        nod = q.begin() -> second;
        q.erase(q.begin());
        for(it = graf[nod].begin(); it != graf[nod].end(); it++)
            {
                nod2 = it -> first;
                cost = it -> second;

                if(d[nod2] > d[nod] + cost)
                {
                    it2 = q.find({d[nod2], nod2});
                    q.erase(it2);
                    d[nod2] = d[nod] + cost;
                    q.insert({d[nod2], nod2});

                }
            }

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

}