Cod sursa(job #2280212)

Utilizator KclaudiuClaudikas Kclaudiu Data 10 noiembrie 2018 12:45:55
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.24 kb
#include <bits/stdc++.h>

using namespace std;

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

const int NMax = 5e4 + 5;
const int INF = 0xf3f3f3;

vector < pair < int, int > > G[NMax];
int D[NMax];

void Dijkstra()
{
    priority_queue < pair < int, int >, vector < pair < int, int > >, greater < pair < int, int > > > pq;
    pq.push (make_pair(0,1));

    while(!pq.empty())
    {
        int node = pq.top().second;
        int value = pq.top().first;
        pq.pop();

        if(D[node] != value) continue;
        for(auto &it: G[node])
        {
            if(value + it.second < D[it.first])
            {
                D[it.first] = value + it.second;
                pq.push (make_pair(D[it.first], it.first));
            }
        }
    }
}

int main()
{
    int n, m;

    f >> n >> m;

    for(int i = 1; i <= m; i++)
    {
        int a, b, c;
        f >> a >> b >> c;

        G[a].push_back(make_pair(b,c));
    }

    for(int i = 2; i <= n; i++) D[i] = INF;
    Dijkstra();

    for(int i = 2; i <= n; i++)
    {
        if(D[i] == INF)
        {
            g << "0 ";
        }
        else
        {
            g << D[i] << " ";
        }
    }

    return 0;
}