Cod sursa(job #2420661)

Utilizator ela_topaTopa Elena ela_topa Data 12 mai 2019 22:07:30
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.2 kb
#include<bits/stdc++.h>
using namespace std;

ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");

constexpr int NX = 500000;
constexpr int inf = 20002;
int N, M;
int viz[NX];
stack <int> S;
int dist[NX];
vector <pair <int, int>> V[NX];
priority_queue < pair <int, int>, vector <pair <int, int>>, greater <pair <int, int>> > pq;

int main()
{
    fin>>N>>M; //citesc nr de noduri si muchiile
    int x, y, c;
    for(int i=1; i<=M; ++i)
    {
        fin>>x>>y>>c;
        V[x].push_back(make_pair(y, c)); //le bag in lista de vecini
    }
    //iau nodul 1 ca sursa
    dist[1] = 0; //ii fac dist 0
    pq.push(make_pair(0, 1)); //bag in pq nodul 1 cu costul 0

    for(int i=2; i<=N; ++i)
    {
        dist[i] = inf;
        pq.push(make_pair(dist[i], i)); //pun nodurile in pq
    }

    while(!pq.empty())
    {
        int nod = pq.top().second;
        for(auto &i: V[nod])
        {
            int oDist = dist[nod] + i.second; //distanta nodului plus cea a vecinului
            if(oDist < dist[i.first]) //optimizez
            {
                dist[i.first] = oDist;
            }
        }
            pq.pop(); //scot
    }

    for(int i=2; i<=N; ++i) //afisez
    fout<<dist[i]<<" ";
    return 0;
}