Cod sursa(job #1968338)

Utilizator trutruvasilicaHuhurez Marius trutruvasilica Data 17 aprilie 2017 17:11:07
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.09 kb
#include <bits/stdc++.h>
#define pi pair<int,int>
#define x first
#define y second
using namespace std;
ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
const int Nmax=50010;
vector<pi>G[Nmax];
vector<pi>::iterator it;
int dist[Nmax];
struct cmp
{
    bool operator()(const int &a,const int &b)
    {
        return dist[a]>dist[b];
    }
};
priority_queue<int,vector<int>,cmp>Q;
void dijkstra(int start)
{
    dist[start]=0;
    Q.push(start);
    while(Q.size())
    {
        int nod=Q.top();
        Q.pop();
        for(it=G[nod].begin();it!=G[nod].end();it++)
        {
            if(dist[it->x]>dist[nod]+it->y)
            {
                dist[it->x]=dist[nod]+it->y;
                Q.push(it->x);
            }
        }
    }
}
int main()
{
    int n,m,i,a,b,c;
    fin>>n>>m;
    while(m--)
    {
        fin>>a>>b>>c;
        G[a].push_back(make_pair(b,c));
    }
    memset(dist,0x3f3f3f3f,sizeof(dist));
    dijkstra(1);
    for(i=2;i<=n;i++)
    {
        if(dist[i]==0x3f3f3f3f) fout<<"-1 ";
        else fout<<dist[i]<<" ";
    }
}