Cod sursa(job #2570715)

Utilizator Tudor_Trasculescu123Tudor Trasculescu Tudor_Trasculescu123 Data 4 martie 2020 18:46:43
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.3 kb
#include <bits/stdc++.h>
#define NMAX 50005

using namespace std;
const int INF = 0x3f3f3f3f;

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

int n, m, x, y, node, cost;
int dist[NMAX], valid[NMAX] ;

struct Acompare
{
    bool operator()(pair <int, int> &p1, pair<int , int> &p2)
    {
        return p1.second > p2.second ;
    }
};
priority_queue < pair <int,int>, vector <pair<int , int>>, Acompare> Q ;
vector < pair <int,int> > v[NMAX]  ;

int main()
{
    fin >> n >> m ;
    for(int i=1; i<=m; i++)
    {
        fin >> x >> y >> cost ;
        v[x].push_back({y, cost}) ;
        v[y].push_back({x, cost}) ;
    }
    for(int i=1; i<=n; i++)
        dist[i] = INF ;
    dist[1] = 0 ;
    Q.push({1, 0}) ;
    while(!Q.empty())
    {
        node = Q.top().first ;
        cost = Q.top().second ;
        Q.pop() ;
        if(dist[node] != cost)
            continue ;
        for(auto it : v[node])
        {
            if(dist[it.first] > cost + it.second)
            {
                dist[it.first] = cost + it.second ;
                Q.push({it.first, dist[it.first]}) ;
            }
        }
    }
    for(int i=2; i<=n; i++)
    {
        if(dist[i] == INF)
            dist[i] = 0;
        fout << dist[i] << " " ;
    }

    return 0;
}