Cod sursa(job #2542340)

Utilizator mihaela.macarie01@yahoo.comMihaela Macarie [email protected] Data 9 februarie 2020 20:22:31
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.44 kb
#include <iostream>
#include <fstream>
#include <queue>
#define N 50005
#define oo (1 << 31)-1

using namespace std;

ifstream x("dijkstra.in");
ofstream y("dijkstra.out");

int n,m;
int d[N];
bool c[N];
vector < pair < int, int > > g[N];

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


priority_queue < int, vector <int>, CD> coada;

void citire()
{
    x>>n>>m;
    int st,dr,lg;
    for(int i=1;i<=m;i++)
    {
        x>>st>>dr>>lg;
        g[st].push_back(make_pair(dr,lg));
    }
}

void dijk(int nod)
{
    for(int i=1;i<=n;i++)
        d[i]=oo;
    d[nod]=0;
    coada.push(nod);
    c[nod]=true;
    while(!coada.empty())
    {
        int nodc=coada.top();
        coada.pop();
        c[nodc]=false;

        for(size_t i=0; i<g[nodc].size(); i++)
        {
            int vec=g[nodc][i].first;
            int cost=g[nodc][i].second;
            if(d[nodc]+cost<d[vec])
            {
                d[vec]=d[nodc]+cost;
                if(c[vec]==false)
                {
                    coada.push(vec);
                    c[vec]=true;
                }
            }
        }
    }
}

void afis()
{
    for(int i=2;i<=n;i++)
    {
        if(d[i]!=oo)
            y<<d[i]<<" ";
        else
            y<<"0 ";
    }
}

int main()
{
    citire();
    dijk(1);
    afis();
    x.close();
    y.close();
    return 0;
}