Cod sursa(job #2887097)

Utilizator ProBatmanBalint Leonard ProBatman Data 8 aprilie 2022 20:06:51
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 2.53 kb
#include <bits/stdc++.h>
#define INF 0x3f3f3f3f

using namespace std;

//typedef int cost;
//typedef int muchie;
using namespace std;

string fisier = "dijkstra";
const int CMAX = 5e4+15;
int muchie , cost , n , m;
int D[CMAX];
int viz[CMAX];
const long long int oo = 1000*50000;
vector < pair < int , int > > graf[CMAX];

ifstream fin(fisier+".in");
ofstream fout(fisier+".out");

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

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

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

void afisare(){
    for(int i=1;i<=n;i++)
    {
        cout << "Nodul: " << i << " : ";
        for(int j=0;j<graf[i].size();j++)
        {
            cout << "(" <<graf[i][j].first << "," << graf[i][j].second << ") ";
        }
        cout << '\n';
    }
}

bool BellmanFord(int start){
    for(int i=1;i<=n;i++)
    {
        viz[i] = 0;
        D[i] = oo;
    }
    D[start] = 0;
    coada.push(start);
    while(!coada.empty()){
        int nodcurent = coada.front();
        viz[nodcurent]++;
        coada.pop();
        if(viz[nodcurent]>=n){
            return false;
        }
        for(int i=0;i<graf[nodcurent].size();i++)
        {
            int vecin = graf[nodcurent][i].first;
            int cost =  graf[nodcurent][i].second;
            if(D[nodcurent]+cost<D[vecin]){
                D[vecin] = D[nodcurent] + cost;
                coada.push(vecin);
            }
        }
    }
    return true;
}

void Dijkstra(int start)
{
    //viz[start] = 1;
    D[start] = 0;
    Q.push(start);
    while(!Q.empty()){
        int nodcurent = Q.top();
        Q.pop();
        for(int i=0;i<graf[nodcurent].size();i++)
        {
            int cost, vecin;
            vecin = graf[nodcurent][i].first;
            cost  = graf[nodcurent][i].second;
            if(D[nodcurent] + cost < D[vecin]){
                D[vecin] = D[nodcurent] + cost;
                Q.push(vecin);
            }
        }
    }
}

int main(){
    citire();

    /*
    if(BellmanFord(1)==true){
        for(int i=2;i<=n;i++)
            fout << D[i] << " ";
    }
    else
        fout << "Ciclu negativ!";
    memset(viz,0,CMAX);
    */
    for(int i=1;i<=n;i++)
        D[i] = oo;
    Dijkstra(1);
    for(int i=2;i<=n;i++)
        fout << D[i] << " ";
    //afisare();
}