Cod sursa(job #2077374)

Utilizator GladrasGrigoriu Stefan-Cosmin Gladras Data 27 noiembrie 2017 22:43:52
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.38 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#define NM 50001
#define INF 200000000

using namespace std;

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

struct arc
{
    int y,c;
};

int n, m;
int inq[NM], d[NM];

struct compara
{
    bool operator()(int x,int y)
    {
        return d[x]>d[y];
    }
};

vector<arc> G[NM];

priority_queue<int, vector<int>, compara> q;

void read();
void Dijkstra(int r);

int main()
{
    read();
    Dijkstra(1);
}

void read()
{
    int i, j, x;
    arc u;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>u.y>>u.c;
        G[x].push_back(u);
    }
}

void Dijkstra(int r)
{
    int i, j, z, y, c, lg;
    for(i=1;i<=n;i++)
        d[i]=INF;
    d[r]=0;
    inq[r]=1;
    q.push(r);
    while(!q.empty())
    {
        z=q.top();
        q.pop();
        inq[z]=0;
        for(i=0;i<G[z].size();i++)
        {
            y=G[z][i].y;
            c=G[z][i].c;
            lg=d[z]+c;
            if(lg<d[y])
            {
                d[y]=lg;
                if(inq[y]==0)
                {
                    inq[y]=1;
                    q.push(y);
                }
            }
        }
    }
    for(i=1;i<=n;i++)
    {
        if(d[i]==INF)
            fout<<0<<" ";
        else
            fout<<d[i]<<" ";
    }
}