Cod sursa(job #2857439)

Utilizator Rares1707Suchea Rares-Andrei Rares1707 Data 25 februarie 2022 16:51:06
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.85 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
using namespace std;

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

const int MAX = 50005, INF = (1 << 30);

int n, m;
int distanta[MAX];
bool inclusInHeap[MAX];

vector < pair < int, int > > legaturi[MAX];

struct Compara
{
    bool operator()(int x, int y)
    {
        return (distanta[x] > distanta[y]);
    }
};

priority_queue < int, vector < int >, Compara > heap;

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

}

void Dijkstra (int nodStart)
{
    for (int i = 1; i <= n; i++)
    {
        distanta[i] = INF;
    }

    distanta[nodStart] = 0;

    heap.push(nodStart);
    inclusInHeap[nodStart] = true;

    while(!heap.empty())
    {
        int nodCurent = heap.top();
        heap.pop();
        inclusInHeap[nodCurent] = false;
        for (unsigned int i = 0; i < legaturi[nodCurent].size(); i++)
        {
            int vecin = legaturi[nodCurent][i].first;
            int cost = legaturi[nodCurent][i].second;

            if (distanta[nodCurent] + cost < distanta[vecin])
            {
                distanta[vecin] = distanta[nodCurent] + cost;
                if (inclusInHeap[vecin] == false)
                {
                    heap.push(vecin);
                    inclusInHeap[vecin] = true;
                }
            }
        }
    }
}

void Afisare()
{
    for (int i = 2; i <= n; i++)
    {
        if (distanta[i] != INF)
        {
            fout << distanta[i] << ' ';
        }
        else
        {
            fout << "0 ";
        }
    }
}

int main()
{
    Citire();
    Dijkstra(1);
    Afisare();
    return 0;
}