Cod sursa(job #2716805)

Utilizator danhHarangus Dan danh Data 5 martie 2021 18:13:18
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.29 kb
#include <iostream>
#include <fstream>
#include <bitset>
#include <vector>
#include <queue>
using namespace std;

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

const int NMAX = 5e4+5;
const int inf = (1LL<<31) - 1;

int dist[NMAX];

priority_queue<pair<int, int>, vector<pair<int, int> >, greater<pair<int, int> > > pq;

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

bitset<NMAX> viz;
int n;

void dijkstra(int x)
{
    for(int i=1; i<=n; i++)
    {
        dist[i] = inf;
    }

    pq.push({0, x});
    dist[x] = 0;

    while(!pq.empty())
    {
        x = pq.top().second;
        pq.pop();

        if(viz[x])
            continue;
        viz[x] = 1;

        for(auto it:v[x])
        {
            if(dist[it.first] > dist[x] + it.second)
            {
                dist[it.first] = dist[x] + it.second;
                pq.push({dist[it.first], it.first});
            }
        }
    }
}

int main()
{
    int m, i, x, c, y;

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

    dijkstra(1);

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

    fin.close();
    fout.close();
    return 0;
}