Cod sursa(job #2553247)

Utilizator victorzarzuZarzu Victor victorzarzu Data 21 februarie 2020 19:36:26
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.32 kb
#include <bits/stdc++.h>
#define oo 0x3f3f3f3f
using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
int n,m,x,y,cost;
vector<pair<int,int>> G[50001];
int dist[50001];
void Read()
{
    f>>n>>m;
    for(int i = 1;i <= m;++i)
    {
        f>>x>>y>>cost;
        G[x].push_back(make_pair(y,cost));
    }
    f.close();
}

void Solve()
{
    memset(dist,oo,sizeof(dist));
    dist[1] = 0;
    set<pair<int,int>> h;
    h.insert(make_pair(0,1));
    while(!h.empty())
    {
        int node = h.begin() -> second;
        int d = h.begin() -> first;
        h.erase(h.begin());

        for(vector<pair<int,int>>::iterator it = G[node].begin();it != G[node].end();++it)
        {
            int to = (*it).first;
            int cost = (*it).second;
            if(dist[to] > dist[node] + cost)
            {
                if(dist[to] != oo)
                    h.erase(h.find(make_pair(dist[to],to)));
                dist[to] = dist[node] + cost;
                h.insert(make_pair(dist[to],to));
            }
        }
    }
}

void Print()
{
    for(int i = 2;i <= n;++i)
        if(dist[i] == oo)
            g<<0<<" ";
        else
            g<<dist[i]<<" ";
    g<<'\n';
    g.close();
}
int main()
{
    Read();
    Solve();
    Print();
    return 0;
}