Cod sursa(job #2201838)

Utilizator ALEx6430Alecs Andru ALEx6430 Data 6 mai 2018 12:01:28
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.44 kb
#include <fstream>
#include <queue>
#include <vector>
#define MAX 50001
#define INF 1000000000
using namespace std;

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

int n, m;
vector< pair<int,int> > v[MAX];
int d[MAX];
bool inCoada[MAX];

struct comparaDistante
{
    bool operator() (int d1, int d2)
    {
        return d[d1]>d[d2];
    }
};
priority_queue<int,vector<int>,comparaDistante> pq;

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

void initializare()
{
    int i;
    for(i=1;i<=n;i++) d[i]=INF;
}

void afisare()
{
    int i;
    for(i=2;i<=n;i++,out<<' ')
        if(d[i]==INF) out<<0;
        else out<<d[i];

}

void djikstra(int k)
{
    d[k]=0; inCoada[k]=true; pq.push(k);
    while(!pq.empty())
    {
        int nod=pq.top(); inCoada[nod]=false; pq.pop();
        for(size_t i=0;i<v[nod].size();i++)
        {
            int vecin=v[nod][i].first;
            int cost=v[nod][i].second;
            if(d[nod]+cost<d[vecin])
            {
                d[vecin]=d[nod]+cost;
                if(inCoada[vecin]==false)
                {
                    inCoada[vecin]=true;
                    pq.push(vecin);
                }
            }
        }
    }
}

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