Cod sursa(job #2771160)

Utilizator andreiiorgulescuandrei iorgulescu andreiiorgulescu Data 25 august 2021 18:20:48
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.37 kb
#include <bits/stdc++.h>

using namespace std;

ifstream in("dijkstra.in");
ofstream out("dijkstra.out");

int n,m,d[50005];
vector<pair<int,int>>a[50005];
priority_queue<pair<int,int>>h;
bool exista[50005];

void citire()
{
    in >> n >> m;
    for (int i = 1; i <= m; i++)
    {
        int x,y,z;
        in >> x >> y >> z;
        a[x].push_back(make_pair(z,y));
    }
    for (int i = 1; i <= 50000; i++)
        d[i] = 2e9;
}

void dijkstra()
{
    d[1] = 0;
    h.push(make_pair(0,1));
    exista[1] = true;
    while (!h.empty())
    {
        pair<int,int>act;
        act = h.top();
        h.pop();
        for (int i = 0; i < a[act.second].size(); i++)
        {
            pair<int,int>vecin;
            vecin.first = a[act.second][i].first;
            vecin.second = a[act.second][i].second;
            if (d[vecin.second] > d[act.second] + vecin.first)
            {
                d[vecin.second] = vecin.first + d[act.second];
                if (exista[vecin.second] == false)
                {
                    h.push(make_pair(-vecin.first,vecin.second));
                    exista[vecin.second] = true;
                }
            }
        }
        exista[act.second] = false;
    }
}

int main()
{
    citire();
    dijkstra();
    for (int i = 2; i <= n; i++)
        out << d[i] << " ";
    return 0;
}