Cod sursa(job #2718437)

Utilizator AndreiAlexandru2k3Ciucan Andrei Alexandru AndreiAlexandru2k3 Data 8 martie 2021 19:05:56
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.39 kb
#include <bits/stdc++.h>
using namespace std;

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

const int NMAX = 50001,
          INF = INT_MAX / 2;

int n, m, vf;
vector <pair<int, int >> G[NMAX];
set<pair<int, int>>Q;
int d[NMAX];

void citire()
{
    f >> n >> m;
    while(m--)
    {
        int x, y, c;
        f >> x >> y >> c;
        G[x].push_back(make_pair(y, c));
    }
}

void Dijkstra(int nod)
{
    for(int i = 1; i <= n; i++)
        d[i] = INF;
    d[nod] = 0;
    Q.insert(make_pair(0, nod));
    while(!Q.empty())
    {
        int nod_curent = Q.begin()->second;
        int dist = Q.begin()->first;
        Q.erase(Q.begin());
        //
        for(auto &x : G[nod_curent])
        {
            int y = x.first;
            int c = x.second;
            if(d[y] > d[nod_curent] + c)
            {
                if(d[y] != INF)
                    Q.erase(Q.find(make_pair(d[y], y)));
                d[y] = d[nod_curent] + c;
                Q.insert(make_pair(d[y], y));
            }
        }
    }
}

void afis()
{
    for(int i = 1; i <= n; i++)
        g << ((d[i] != INF) ? d[i] : -1) << ' ';
}

int main()
{
    citire();
    Dijkstra(1);
    for (int i = 2; i <= n; ++i)
    {
        if (d[i] == INF)
        {
            d[i] = 0;
        }
        g << d[i] << ' ';
    }
    g << '\n';
    return 0;
}