Cod sursa(job #2357163)

Utilizator Luca19Hritcu Luca Luca19 Data 27 februarie 2019 10:24:41
Problema Algoritmul lui Dijkstra Scor 40
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.29 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <set>
#include <queue>
#include <cstring>
#define Nmax 50003
#define INF 0x3f3f3f3f

using namespace std;

ifstream f("dijkstra.in");
ofstream g("dijkstra.out");

int n, m, x, y, c;
vector <pair <int, int> > v[Nmax];
int d[Nmax];
bool ex[Nmax];

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

};

priority_queue <int, vector <int>, cmp> Q;

void dijkstra(int start)
{
    memset(d, INF, sizeof(d));
    d[1]=0;
    ex[1]=1;
    Q.push(1);
    while(!Q.empty())
    {
        int x=Q.top();
        Q.pop();
        ex[x]=0;
        for (int i = 0, l=v[x].size(); i < l; i++)
        {
            int y=v[x][i].first;
            int c=v[x][i].second;
            if(d[y]>d[x]+c)
            {
                d[y]=d[x]+c;
                if(ex[y] == 0)
                {
                    ex[y]=1;
                    Q.push(y);
                }
            }
        }
    }
    for (int i = 2; i <= n; i++)
        if(d[i] == INF) g << "0 ";
        else g << d[i] << " ";
}

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

    return 0;
}