Cod sursa(job #2669436)

Utilizator loraclorac lorac lorac Data 6 noiembrie 2020 22:45:44
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.18 kb
#include <bits/stdc++.h>
using namespace std;
ifstream in("bellmanford.in");
ofstream out("bellmanford.out");
int n,m,x,y,c;
const int lim=5e4+5;
const int inf=2e9+7;
struct Op
{
    int nod;
    int cost;
    int app;
};
bool ok[lim];
int dist[lim];
vector<Op> vec[lim];
set<pair<int,int> > s;
int main()
{
    in>>n>>m;
    for(int i=1;i<=m;++i)
    {
        in>>x>>y>>c;
        vec[x].push_back({y,c,0});
    }
    dist[1]=0;
    for(int i=2;i<=n;++i)
        dist[i]=inf;
    s.insert({0,1});
    while(!s.empty())
    {
        int cost=(*(s.begin())).first;
        int nod=(*(s.begin())).second;
        s.erase(s.begin());
        ok[nod]=false;
        for(auto &x:vec[nod])
        if(dist[x.nod]>cost+x.cost)
        {
            ++x.app;
            if(x.app==n)
            {
                out<<"Ciclu negativ!"<<'\n';
                return 0;
            }
            if(ok[x.nod]==true)
                s.erase(s.find({dist[x.nod],x.nod}));
            ok[x.nod]=true;
            dist[x.nod]=cost+x.cost;
            s.insert({dist[x.nod],x.nod});
        }
    }
    for(int i=2;i<=n;++i)
        out<<dist[i]<<' ';
    return 0;
}