Cod sursa(job #535519)

Utilizator SadmannCornigeanu Calin Sadmann Data 17 februarie 2011 13:02:48
Problema Algoritmul lui Dijkstra Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.49 kb
#include<stdio.h>
#include<algorithm>
#include<queue>
#include<list>
using namespace std;
#define INF 1<<30
#define MAXSIZE 50001
#define cost first
#define poz second

vector<int> dist;
int from,to,cost,n,m,i;
list< pair<int,int> > graph[MAXSIZE];
priority_queue< pair<int,int>,vector< pair<int,int> >,greater<pair<int,int> > > myHeap;

void dijkstra(int);
inline bool isInf(int number) { return (number == INF); };

FILE *in,*out;
int main()
{
    in=fopen("dijkstra.in","rt");
    out=fopen("dijkstra.out","wt");
    fscanf(in,"%d %d",&n,&m);
    dist.resize(n+1);
    for(i=1;i<=n;i++)
    {
        fscanf(in,"%d %d %d",&from,&to,&cost);
        graph[from].push_back(make_pair(cost,to));
    }
    fclose(in);

    dijkstra(1);

    for(i=2;i<=n;i++)
        fprintf(out,"%d ",dist[i]==INF ? 0:dist[i]);
    fclose(out);
    return 0;
}

void dijkstra(int StartNode)
{
    dist.assign(n+1,INF);
    dist[StartNode]=0;
    pair<int,int> CurrentNode;
    list< pair<int,int> >::iterator vecin;
    myHeap.push(make_pair(0,StartNode));
    while(!myHeap.empty())
    {
        CurrentNode=myHeap.top();
        myHeap.pop();
        for(vecin=graph[CurrentNode.poz].begin();vecin!=graph[CurrentNode.poz].end();++vecin)
            if(dist[vecin->poz]>dist[CurrentNode.poz]+vecin->cost)
            {
                dist[vecin->poz]=dist[CurrentNode.poz]+vecin->cost;
                myHeap.push(make_pair(dist[vecin->poz],vecin->poz));
            }
    }
}