Cod sursa(job #1548495)

Utilizator tudormaximTudor Maxim tudormaxim Data 10 decembrie 2015 23:21:34
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.37 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;
const int nmax = 5e4+5;
const int inf = (1<<29);
vector <pair<int,int> > g[nmax];
int dist[nmax];

inline bool cmp(const int &x, const int &y)
{
    return dist[x] > dist[y];
}

void dijkstra()
{
    vector <int> h;
    int dad, son, i, cost;
    h.push_back(1);
    make_heap(h.begin(), h.end(), cmp);
    while(!h.empty())
    {
        dad=h.front();
        pop_heap(h.begin(), h.end(), cmp);
        h.pop_back();
        for(i=0; i<g[dad].size(); i++)
        {
            son=g[dad][i].first;
            cost=g[dad][i].second;
            if(dist[son] > dist[dad]+cost)
            {
                dist[son]=dist[dad]+cost;
                h.push_back(son);
                push_heap(h.begin(), h.end(), cmp);
            }
        }
    }
}

int main()
{
    ifstream fin ("dijkstra.in");
    ofstream fout ("dijkstra.out");
    ios_base::sync_with_stdio(false);
    int n, m, i, x, y, c;
    fin >> n >> m;
    for(i=1; i<=m; i++)
    {
        fin >> x  >> y >> c;
        g[x].push_back(make_pair(y, c));
    }
    for(i=2; i<=n; i++)
        dist[i]=inf;
    dijkstra();
    for(i=2; i<=n; i++)
    {
        if(dist[i]==inf) dist[i]=0;
        fout << dist[i] << " ";
    }
    fin.close();
    fout.close();
    return 0;
}