Cod sursa(job #2476356)

Utilizator filiptudose2007Tudose Filip filiptudose2007 Data 18 octombrie 2019 18:20:09
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.15 kb
#include <bits/stdc++.h>
using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
vector <pair<int,int>>G[50005];
priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>>Q;
int i,n,m,x,y,cost,k,a,D[50005];
bool sel[50005];
void dijkstra(int p)
{
    for(auto i: G[p])
    {
        Q.push(i);
        D[i.second]=i.first;
    }
    sel[p]=true;
    while(!Q.empty())
    {
        while(!Q.empty() && sel[Q.top().second])
            Q.pop();
        if(!Q.empty())
        {
            k=Q.top().second;

            sel[k]=true;
            Q.pop();
            for(auto i:G[k])
            {
                if(D[i.second]>D[k]+i.first)
                {
                    D[i.second]=D[k]+i.first;
                    Q.push(i);
                }
            }
        }
    }
}
int main()
{
    f>>n>>m;
    for(i=1; i<=m; ++i)
    {
        f>>x>>y>>cost;
        G[x].push_back({cost,y});
    }

    for(i=2; i<=n; ++i)D[i]=INT_MAX;
    dijkstra(1);
    for(i=2; i<=n; ++i)
    {
        if(D[i]==INT_MAX)g<<0<<' ';
        g<<D[i]<<' ';
    }
    g<<'\n';
    return 0;
}