Cod sursa(job #2505678)

Utilizator VeliceaFabianVelicea Fabian - Pavel VeliceaFabian Data 7 decembrie 2019 10:19:05
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.3 kb
#include <bits/stdc++.h>

using namespace std;
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");
int n,m;
const int Max=50005;
vector<pair<int,int>>v[Max];
int rep[Max];
bool incoada[Max];
int d[Max];
struct compara{
bool operator()(int x,int y)
{
    return d[x]>d[y];
}

};
priority_queue<int,vector<int>,compara>q;
void citire()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y,z;
        fin>>x>>y>>z;
        v[x].push_back({y,z});
    }
}
int bellman()
{
    q.push(1);
    for(int i=2;i<=n;i++)
        d[i]=INT_MAX;
    while(!q.empty())
    {
        int nod=q.top();
        q.pop();incoada[nod]=0;
        for(int j=0;j<v[nod].size();j++)
        {
            int vecin=v[nod][j].first;
            int cost=v[nod][j].second;
            if(d[nod]+cost<d[vecin])
            {
                d[vecin]=d[nod]+cost;
                rep[vecin]++;
                if(rep[vecin]>n)
                    return 0;
                if(incoada[vecin]==0)
                {
                    incoada[vecin]=1;
                    q.push(vecin);
                }
            }
        }
    }
    return 1;
}
int main()
{
citire();
if(!bellman())
    fout<<"Ciclu negativ!";
else for(int i=2;i<=n;i++)fout<<d[i]<<" ";
    return 0;
}