Cod sursa(job #2575812)

Utilizator danhHarangus Dan danh Data 6 martie 2020 15:35:03
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.46 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

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

const int N = 50005;
const int INF = 0x3f3f3f3f;

vector<pair<int, int> > v[N];
int dist[N];
bool viz[N];

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

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

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

}

int main()
{
    int n, m, i, j, x, y, c;
    fin>>n>>m;

    for(i=1; i<=m; i++)
    {
        fin>>x>>y>>c;
        v[x].push_back({y, c});
    }

    for(i=1; i<=n; i++)
    {
        dist[i] = INF;
    }

    Dijktra(1);

    for(i=2; i<=n; i++)
    {
        if(dist[i] != INF)
        {
            fout<<dist[i]<<' ';
        }
        else
        {
            fout<<0<<' ';
        }
    }
    fin.close();
    fout.close()
    return 0;
}