Cod sursa(job #2076630)

Utilizator valentinoMoldovan Rares valentino Data 26 noiembrie 2017 21:20:40
Problema Algoritmul lui Dijkstra Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.43 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, use[NMax];
vector < pair < int, int > > graf[NMax];
vector < int > d;

struct compare
{
    bool operator()(const int& i, const int& j)
    {
        return d[i] < d[j];
    }
};

multiset < int, compare > q;

int main()
{
    int x, y, c, nod, nod2, cost;
    vector < pair < int, int > > :: iterator it;
    f >> n >> m;
    d.resize(n + 1);
    q.insert(1);
    for(int i = 2; i <= n; ++i)
    {
        d[i] = inf;
        q.insert(i);
    }

    for(int i = 1; i <= m; ++i)
    {
        f >> x >> y >> c;
        graf[x].push_back({y, c});
    }
    while(!q.empty())
    {
        nod = *q.begin();
        q.erase(q.begin());
        if(!use[nod])
        {
            use[nod] = 1;
            for(it = graf[nod].begin(); it != graf[nod].end(); it++)
            {
                nod2 = it -> first;
                cost = it -> second;

                if(d[nod2] > d[nod] + cost)
                {
                    d[nod2] = d[nod] + cost;
                    q.insert(nod2);
                }
            }
        }
    }
    for(int i = 2; i <= n; ++i)
    {
        if(d[i] == inf) g << 0 << ' ';
        else g << d[i] << ' ';
    }

}