Cod sursa(job #1346056)

Utilizator macajouMaca George macajou Data 18 februarie 2015 00:05:41
Problema Algoritmul lui Dijkstra Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 1.63 kb
#include <cstdio>
#include <vector>
#include <queue>
#define nmax 50010
#define inf 1<<30

using namespace std;

struct vecini
{
    int vec,c;
};

vector<vecini> v[nmax];
int n,m,cost[nmax],prez[nmax];

void citire()
{
    int i,x;
    vecini vc;
    scanf("%d%d",&n,&m);
    for(i=1;i<=m;i++)
        {
            scanf("%d%d%d",&x,&vc.vec,&vc.c);
            v[x].push_back(vc);
        }
    for(i=2;i<=n;i++)
        cost[i]=inf;
}

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

void dijkstra()
{
    priority_queue<int, vector<int>, cmp> q;
    q.push(1);
    vecini vc;
    int p,i,c;
    while(!q.empty())
          {
              p=q.top();
              q.pop();
              for(i=0;i<v[p].size();i++)
                  {
                      vc=v[p][i];
                      c=cost[p]+vc.c;
                      if(c<cost[vc.vec])
                         {
                             cost[vc.vec]=c;
                             if(!prez[vc.vec])
                                {
                                    prez[vc.vec]=1;
                                    q.push(vc.vec);
                                }
                         }
                  }
              prez[vc.vec]=0;
          }
}

void afisare()
{
    int i;
    for(i=2;i<=n;i++)
        if(cost[i]==inf)
           printf("0 ");
        else printf("%d ",cost[i]);
}

int main()
{
    freopen("dijkstra.in","r",stdin);
    freopen("dijkstra.out","w",stdout);
    citire();
    dijkstra();
    afisare();

    return 0;
}