Cod sursa(job #1619283)

Utilizator SlevySlevoaca Stefan-Gabriel Slevy Data 28 februarie 2016 14:46:45
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.26 kb
#include <bits/stdc++.h>
#define oo 1<<30

using namespace std;

ifstream in("dijkstra.in");
ofstream out("dijkstra.out");
const int NMAX = 50001;
vector<pair<int,int> > muchii[NMAX];
bitset<NMAX> mark;
set<pair<int,int> > heap;
int n,m;
int values[NMAX];

void citire()
{
    in>>n>>m;
    int x,y,z;
    for(int i=1;i<=m;i++)
    {
        in>>x>>y>>z;
        muchii[x].push_back(make_pair(y,z));
    }
    in.close();
}

void dijsktra()
{
    for(int i = 2;i<=n;i++)
        values[i] = oo;
    heap.insert(make_pair(0,1));
    while(heap.size() > 0)
    {
        int y = (*heap.begin()).second;
        mark.set(y);
        int target,cost;
        heap.erase(heap.begin());
        for(unsigned int i=0;i<muchii[y].size();i++)
        {
           target = muchii[y][i].first;
           cost = muchii[y][i].second;
           if(!mark.test(target) && values[target] > values[y] + cost)
            {
                values[target] = values[y] + cost;
                heap.insert(make_pair(values[target],target));
            }
        }
    }
}

int main()
{
    citire();
    dijsktra();
    for(int i=2;i<=n;i++)
        if(values[i]==oo)
        out<<0<<" ";
    else
           out<<values[i]<<" ";
    return 0;
}