Cod sursa(job #2191381)

Utilizator PaulCbnCiobanu Paul PaulCbn Data 2 aprilie 2018 18:31:48
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.63 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

#define NMAX 50005
#define inf 0x3f3f3f3f

using namespace std;

int N,M;
vector<pair<int,int> > graf[NMAX];

void citire(char fisier[])
{
    ifstream fin(fisier);
    fin>>N>>M;
    for(int i=0; i<M; i++)
    {
        int n1,n2,c;
        fin>>n1>>n2>>c;
        graf[n1].push_back(make_pair(n2,c));
       // graf[n2].push_back(make_pair(n1,c));
    }
    fin.close();
}


int d[NMAX];
int viz[NMAX];
priority_queue<pair<int,int> > q;
void djikstra(int s)
{
    for(int i=1; i<=N; i++)
    {
        d[i] = inf;
        viz[i] = 0;
    }

    d[s]=0;

    q.push(make_pair(0,s));
    while(!q.empty())
    {
        int nod_curent = q.top().second;
        int cost_curent = -q.top().first;
        q.pop();

        if(viz[nod_curent])
            continue;
        viz[nod_curent] = 1;

        for(vector<pair<int,int> >::iterator ii=graf[nod_curent].begin(); ii!=graf[nod_curent].end(); ii++)
        {
            ///pentru fiecare vecin al lui nod_curent:
            int vecin = ii->first;
            int cost = ii->second;
            if(viz[vecin])
                continue;

            if(cost_curent + cost < d[vecin])
            {
                d[vecin] = cost_curent + cost;
                q.push(make_pair(-d[vecin],vecin));
            }
        }
    }
}

int main()
{
     ofstream cout("dijkstra.out");
    citire("dijkstra.in");
    djikstra(1);
    for(int i=2; i<=N; i++)
        if(d[i] == inf)
            cout<<"0 ";
        else
            cout<<d[i]<<" ";
    return 0;
}