Cod sursa(job #2575068)

Utilizator Iosif02Oprea Iosif Iosif02 Data 6 martie 2020 11:29:38
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.55 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

const int MAX = 50005;
int n, m, d[MAX], oo = (1 << 30);
bool vizitat[MAX];

struct compara {
    bool operator()(int a, int b) {
        return d[a] > d[b];
    }
};

vector < pair <int, int> > muchii[MAX];
priority_queue <int, vector <int>, compara> coada;

void citire() {
    in >> n >> m;
    int a, b, c;
    for(int i = 1; i <= m; i++) {
        in >> a >> b >> c;
        muchii[a].push_back(make_pair(b, c));
    }
    for(int i = 1; i <= n; i++)
        d[i] = oo;
}

void Dijkstra(int nodStart) {
    vizitat[nodStart] = true;
    d[nodStart] = 0;
    coada.push(nodStart);
    while(!coada.empty()) {
        int nodCurent = coada.top();
        coada.pop();
        vizitat[nodCurent] = false;
        for(unsigned int i = 0; i < muchii[nodCurent].size(); i++) {
            int vecin = muchii[nodCurent][i].first;
            int cost = muchii[nodCurent][i].second;
            if(d[nodCurent] + cost < d[vecin]) {
                d[vecin] = d[nodCurent] + cost;
                if(!vizitat[vecin]) {
                    vizitat[vecin] = true;
                    coada.push(vecin);
                }
            }
        }
    }
}

void afisare() {
    for(int i = 2; i <= n; i++)
        if(d[i] != oo)
            out << d[i] << " ";
        else out << 0 << " ";
}

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