Cod sursa(job #876809)

Utilizator Viva12Ferentz Sergiu Viva12 Data 12 februarie 2013 10:21:32
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.62 kb
#include <cstdio>
#include <vector>
#define lim 50001
#define oo (1<<30)-1
#include <queue>
using namespace std;
FILE *inFile = fopen("dijkstra.in","r");
FILE *outFile = fopen("dijkstra.out","w");
int n,m;

struct nod
{
    int vf,cost;
};

int cost[lim];
bool viz[lim];

struct cmp
{
    bool operator()(int &x, int &y)const
    {
        return cost[x] > cost[y];
    }
};

priority_queue<int,vector<int>,cmp> Q;
vector<nod>graf[lim];

void citire()
{
    fscanf(inFile,"%d %d",&n,&m);
    for(int i =0 ; i < m ; i++)
    {
        int x,y,c;
        fscanf(inFile,"%d %d %d",&x,&y,&c);
        nod K;
        K.vf = y;
        K.cost = c;
        graf[x].push_back(K);
    }

}



void initialize(int start)
{
    for(int i = 1; i <= n; i++)
    {
        cost[i] = oo;
        viz[i] = false;
    }
    cost[start] = 0;
}

void dijkstra(int start)
{
    Q.push(start);
    viz[start] = true;
    while (!Q.empty())
    {
        int min = Q.top();
        Q.pop();
        for(int i = 0; i < graf[min].size();i++)
        {
            if(viz[graf[min][i].vf] == false)
            if(cost[min] + graf[min][i].cost < cost[graf[min][i].vf])
            {
                cost[graf[min][i].vf] = cost[min] + graf[min][i].cost;
                Q.push(graf[min][i].vf);
            }
        }
        viz[start] = true;
    }

    for(int i = 0 ; i <= n; i++)
        if(cost[i] == oo)
        cost[i] =0;
}
int main()
{
    citire();
    initialize(1);
    dijkstra(1);
    for(int i =2; i <=n; i++)
    {
        fprintf(outFile,"%d ",cost[i]);
    }

    return 0;
}