Cod sursa(job #2630171)

Utilizator iulianarsenoiuArsenoiu Iulian iulianarsenoiu Data 24 iunie 2020 16:34:09
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.22 kb
#include <bits/stdc++.h>

using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
const int oo = INT_MAX;
vector<pair<int,int>> G[100005];
int n,m,d[100005];
bool sel[100005];
void Dijkstra(int pl)
{
    priority_queue <pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> h;
    for(int i=1;i<=n;i++)
    {
        d[i]=oo;
    }
    d[pl]=0;
    for(auto it : G[pl])
    {
        d[it.second]=it.first;
        h.push(it);
    }
    while(!h.empty())
    {
        while(!h.empty() && sel[h.top().second])
        {
            h.pop();
        }
        if(h.empty())
        {
            return;
        }
        pair<int,int> k=h.top();
        h.pop();
        sel[k.second]=true;
        for(auto it : G[k.second])
        {
            if(k.first+it.first<d[it.second])
            {
                d[it.second]=k.first+it.first;
                h.push({d[it.second],it.second});
            }
        }
    }
}
int main()
{
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y,c;
        f>>x>>y>>c;
        G[x].push_back({c,y});
    }
    Dijkstra(1);
    for(int i=2;i<=n;i++)
    {
        g<<d[i]<<' ';
    }
    g<<'\n';
    return 0;
}