Cod sursa(job #2829404)

Utilizator Mihai_EduardMihai Eduard Mihai_Eduard Data 8 ianuarie 2022 16:23:35
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.24 kb
#include <bits/stdc++.h>

using namespace std;

ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
const int NMAX=50005;
const int inf=2e9;

int N, M, d[NMAX];
vector<pair<int,int>> g[NMAX];
struct element{
    int nod, cost;
};
struct compare{
    bool operator()(element &A, element &B){
        return A.cost>B.cost;
    }
};
priority_queue<element,vector<element>,compare> q;

void Dijkstra(int sursa)
{
    for(int i=1;i<=N;i++)
        d[i]=inf;
    d[sursa]=0;
    q.push({sursa,0});
    element x;
    while(!q.empty()){
        x=q.top();
        q.pop();
        if(x.cost!=d[x.nod]) /// am gasit un nod duplicat neactualizat
            continue;
        for(auto next: g[x.nod]){
            if(d[x.nod]+next.second<d[next.first]){
                d[next.first]=d[x.nod]+next.second;
                q.push({next.first,d[next.first]});
            }
        }
    }
}

int main()
{
    fin>>N>>M;
    int x, y, z;
    for(int i=1;i<=M;i++){
        fin>>x>>y>>z;
        g[x].push_back({y,z});
    }

    Dijkstra(1);

    for(int i=2;i<=N;i++)
        if(d[i]==inf)
            fout<<0<<' ';
        else
            fout<<d[i]<<' ';

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