Cod sursa(job #2402106)

Utilizator danhHarangus Dan danh Data 10 aprilie 2019 12:41:05
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.5 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <climits>
using namespace std;

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

const int MAX = 50005;

vector<pair<int, int> >v[MAX];

int dist[MAX];
bool viz[MAX];

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

priority_queue<int, vector<int>, comp> pq;

void dijkstra(int x)
{
    dist[x] = 0;
    pq.push(x);
    viz[x] = 1;
    while(!pq.empty())
    {
        x = pq.top();
        pq.pop();
        viz[x] = 0;

        for(int i=0; i<v[x].size(); i++)
        {
            int cost, nod;
            nod = v[x][i].first;
            cost = v[x][i].second;

            if(dist[x] + cost < dist[nod])
            {
                dist[nod] = dist[x] + cost;
                if(!viz[nod])
                {
                    pq.push(nod);
                    viz[nod] = 1;
                }
            }
        }
    }
}


int main()
{
    int n, m;

    fin>>n>>m;

    int i, a, b, c;
    for(i=1; i<=m; i++)
    {
        fin>>a>>b>>c;
        v[a].push_back(make_pair(b, c));
    }

    for(i=1; i<=n; i++)
    {
        dist[i] = INT_MAX;
    }

    dijkstra(1);

    for(i=2; i<=n; i++)
    {
        if(dist[i] == INT_MAX)
        {
            fout<<"0 ";
        }
        else
        {
            fout<<dist[i]<<' ';
        }
    }

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