Cod sursa(job #2499237)

Utilizator coculescugabiCoculescu Gabriel coculescugabi Data 25 noiembrie 2019 18:34:18
Problema Algoritmul lui Dijkstra Scor 70
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.76 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>

using namespace std;

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

const int NMax = 50005;
const int oo = (1 << 30); // max int

int N, M;
int D[NMax]; // distance
bool Inqueue[NMax]; // inqueue[i] = true if node is visited

vector < pair < int, int > > G[NMax];

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

priority_queue < int, vector < int >, compdist> Queue;
// push nodes ascending regarding the cost

void Read() {
    fin >> N >> M;
    for(int i = 1; i <= M; i++) {
        int x, y, c;
        fin >> x >> y >> c;
        G[x].push_back(make_pair(y,c));
    }
}

void Dijkstra(int nodStart) {
    for(int i = 1; i <= N; i++) {
        D[i] = oo;
    }
    D[nodStart] = 0;
    Queue.push(nodStart);
    Inqueue[nodStart] = true;
    while(!Queue.empty()) {
        int nodCurrent = Queue.top(); // take node with smallest cost
        //Inqueue[nodCurrent] = false;
        for(unsigned int i = 0; i < G[nodCurrent].size(); i++) {
            int Neighbour = G[nodCurrent][i].first;
            int Cost = G[nodCurrent][i].second;
            if(D[nodCurrent] + Cost < D[Neighbour]) {
                D[Neighbour] = D[nodCurrent] + Cost;
                if(Inqueue[Neighbour] == false) {
                    Queue.push(Neighbour);
                    Inqueue[Neighbour] = true;
                }
            }
        }
        Queue.pop();
    }
}

void Write() {
    for(int i = 2; i <= N; i++) {
        if(D[i] != oo)
            fout << D[i] << " ";
        else
            fout << "0 ";
    }
}

int main()
{
    Read();
    Dijkstra(1);
    Write();
    for (int i = 1 ; i <= N; i++) {
        cout<< Inqueue[i] << " ";
    }
    return 0;
}