Cod sursa(job #2342205)

Utilizator radurotaruRotaru Radu Stefan radurotaru Data 12 februarie 2019 17:40:55
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.22 kb
#include <fstream>
#include <vector>
#include <queue>
#include <set>

using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");

typedef pair <int, int> P;
struct arc
{
    int x,y;
    bool operator < (const arc &other)const
    {
        return y< other.y;
    }
};
int n,d[50002],m,p,x,y,z;
bool a[50002];
multiset <arc> v[50002];
multiset <arc> :: iterator itr;
priority_queue < P, vector<P>, greater<P> > Q;

void dijkstra2(int q)
{
    Q.push(make_pair(0, q));
    for(int i=1; i<=n; i++)
        d[i]=999999999;
    d[q]=0;
    a[q]=1;
    while(!Q.empty())
    {
        int w=Q.top().second;
        Q.pop();
        for(itr=v[w].begin(); itr!=v[w].end(); itr++)
        {
            if(!a[itr->x] && d[itr->x]>d[w]+itr->y)
            {
                d[itr->x]=d[w]+itr->y;
                a[itr->x]=1;
                Q.push(make_pair(d[itr->x], itr->x));
            }
        }
    }
}

int main()
{
    f>>n>>m;
    for(int i=1; i<=m; i++)
    {
        f>>x>>y>>z;
        v[x].insert({y,z});
    }
    dijkstra2(1);
    for(int i=2; i<=n; i++)
    {
        if(a[i])
            g<<d[i]<<" ";
        else
            g<<0<<" ";
    }
    return 0;
}