Cod sursa(job #2856610)

Utilizator Iordache_CezarIordache Cezar Iordache_Cezar Data 24 februarie 2022 10:10:47
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.38 kb
#include <bits/stdc++.h>
#define INF 1000000004
#define NMAX 50004

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

int n, m, start;
int dp[NMAX];
vector < pair <int, int> > G[NMAX];
set < pair <int, int> > S;

void citire();
void Dijkstra(int start);
void traseu(int x);

int main()
{
    citire();
    Dijkstra(1);
    for (int i = 2; i <= n; i++)
    {
        if (dp[i] == INF)
            fout << -1;
        else
        {
            fout << dp[i];
            //fout << ' ' << nr[i] << ' ';
        }
        //traseu(i);
        fout << ' ';
    }
    return 0;
}

void citire()
{
    int x, y, c;
    fin >> n >> m;
    for (int i = 1; i <= m; i++)
    {
        fin >> x >> y >> c;
        G[x].push_back({y, c});
    }
    for (int i = 0; i <= n; i++)
        dp[i] = INF;
}

void Dijkstra(int start)
{
    dp[start] = 0;
    S.insert({0, start});

    while (!S.empty())
    {
        int nod = S.begin()->second;
        S.erase(S.begin());

        for (int i = 0; i < G[nod].size(); i++)
        {
            pair <int, int> vecin = G[nod][i];
            int vf = vecin.first;
            int cost = vecin.second;
            if (dp[vf] > dp[nod] + cost)
            {
                dp[vf] = dp[nod] + cost;
                S.insert({dp[vf], vf});
            }
        }
    }
}