Cod sursa(job #3215836)

Utilizator BeneIonut2208Bene Ionut-Matei BeneIonut2208 Data 15 martie 2024 13:22:08
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.51 kb
#include <iostream>
#include <fstream>
#include <queue>
#define INF 2000000000

using namespace std;

ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
int n, m;
int D[50005], inCoada[50005];
vector < pair <int, int> > adj[50005];
struct comp
{
    bool operator() (int x, int y)
    {
        return D[x] > D[y];
    }
};


priority_queue <int, vector <int>, comp> Q;

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

void afisare()
{
    for(int i = 2; i <= n; i++)
        if(D[i] == INF)
            fout << 0 << ' ';
        else
            fout << D[i] << ' ';
}

void Dijkstra(int start)
{
    for(int i = 1; i <= n; i++)
        D[i] = INF;
    D[start] = 0;
    Q.push(start);
    inCoada[start] = 1;
    while(!Q.empty())
    {
        int nod = Q.top();
        Q.pop();
        inCoada[nod] = 0;
        int l = adj[nod].size();
        for(int i = 0; i < l; i++)
        {
            int vecin = adj[nod][i].first;
            int cost = adj[nod][i].second;
            if(D[nod] + cost < D[vecin])
            {
                D[vecin] = D[nod] + cost;
                if(inCoada[vecin] == 0)
                {
                    Q.push(vecin);
                    inCoada[vecin] = 1;
                }
            }
        }
    }
}

int main()
{
    citire();
    Dijkstra(1);
    afisare();
    return 0;
}