Cod sursa(job #1510321)

Utilizator forever16Alex M forever16 Data 24 octombrie 2015 20:22:17
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.28 kb
#include <iostream>
#include<fstream>
#include<vector>
#include<queue>

#define inf 1<<30
#define maxn 50001
using namespace std;
    ifstream in("dijkstra.in");
    ofstream out("dijkstra.out");


int n, m;
int Cost[maxn];
vector <pair <int, int> > G[maxn];
queue <pair <int, int> > q;

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

void init()
{
    q.push(make_pair(1, 0));
    for(int i=2; i<=n; i++)
        Cost[i]=inf;

}

void dijkstra()
{
    init();

    while(!q.empty())
    {
        int nodCurent=q.front().first;
        int costCurent=q.front().second;

        q.pop();

        for(int i=0; i<G[nodCurent].size(); i++)

            {int vecin= G[nodCurent][i].first;
            int costVecin = G[nodCurent][i].second;

        if(costVecin + costCurent< Cost[vecin])

            {Cost[vecin] = costVecin + costCurent;
            q.push(make_pair(vecin, Cost[vecin]));
           }
        }
    }
}

void write()
{
     for(int i=2; i<=n; i++)
        {if(Cost[i]==inf )
            out<<"0"<<" ";
        else out<<Cost[i]<<" ";
    }
}

int main()
{
    read();
    dijkstra();
    write();
    return 0;
}