Cod sursa(job #2549636)

Utilizator andrei42Oandrei42O andrei42O Data 17 februarie 2020 21:08:14
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.07 kb
#include <bits/stdc++.h>
using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
const int N = 50010;
const int oo = 1000000000;
vector <pair<int, int>> v[N];
priority_queue <pair<int, int>> pq;
int d[N], n, m;
int main()
{
    f >> n >> m;
    for(; m; m--)
    {
        int x, y, c;
        f >> x >> y >> c;
        v[x].push_back({y, c});
    }
    for(int i = 2; i <= n; i++)
        d[i] = oo;
    pq.push({0, 1}); /// cost , nod
    while(!pq.empty())
    {
        int nod, cost;
        tie(cost, nod) = pq.top();
        cost = -cost;
        pq.pop();
        if(d[nod] == cost)
        {
            for(auto it: v[nod])
            {
                if(d[it.first] > cost + it.second)
                {
                    d[it.first] = cost + it.second;
                    pq.push({-d[it.first], it.first});
                }
            }
        }
    }
    for(int i = 2; i <= n; i++)
    {
        if(d[i] == oo)
            g << 0 << ' ';
        else
            g << d[i] << ' ';
    }
    return 0;
}