Cod sursa(job #2418998)

Utilizator danhHarangus Dan danh Data 7 mai 2019 12:39:55
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.47 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
using namespace std;

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

const int NMAX = 50005;

vector<pair<int, int> >v[NMAX];

int dist[NMAX];
bool viz[NMAX];

struct comp
{
    bool operator()(int a, int b)
    {
        return dist[a] > dist[b];
    }
};

priority_queue<int, vector<int>, comp> pq;

void dijkstra(int x)
{
    viz[x] = true;
    dist[x] = 0;
    pq.push(x);
    while(!pq.empty())
    {
        x = pq.top();
        pq.pop();
        viz[x] = false;
        for(int i = 0; i < v[x].size(); i++)
        {
            int nod, cost;
            nod = v[x][i].first;
            cost = v[x][i].second;
            if(dist[x] + cost < dist[nod])
            {
                dist[nod] = dist[x] + cost;
                if(!viz[nod])
                {
                    pq.push(nod);
                    viz[nod] = true;
                }
            }
        }
    }
}

int main()
{
    int n, i, m;
    fin>>n>>m;

    int x, y, cost;
    for(i = 0; i < m; i++)
    {
        fin>>x>>y>>cost;
        v[x].push_back(make_pair(y, cost));
    }

    for(i = 0; i <= n; i++)
    {
        dist[i] = INT_MAX;
    }

    dijkstra(1);

    for(i = 2; i <= n; i++)
    {
        if(dist[i] != INT_MAX)
        {
            fout<<dist[i]<<' ';
        }
        else
        {
            fout<<0<<' ';
        }
    }
}