Cod sursa(job #2481633)

Utilizator Dan_BDan Bugnariu Dan_B Data 27 octombrie 2019 10:15:39
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.26 kb
#include <bits/stdc++.h>
#define M 50005
#define INF INT_MAX-1
using namespace std;
ifstream in("bellmanford.in");
ofstream out("bellmanford.out");

int n,m,d[M],v[M];
vector<pair<int,int> >lista[M];
deque<int>q;
bool inq[M];

void citire()
{
    in>>n>>m;
    for(int i=0;i<m;i++)
    {
        int x,y,c;
        in>>x>>y>>c;
        lista[x].push_back({y,c});
    }
}
void bellman(int nod)
{
    for(int i=1;i<=n;i++)
    {
        v[i]=0;
        d[i]=INF;
    }
    d[nod]=0;
    q.push_back(nod);
    inq[nod]=true;
    while(!q.empty())
    {
        int nodc=q.front();
        v[nodc]++;
        if(v[nodc]>n)
        {
            out<<"Ciclu negativ!";
            return;
        }
        inq[nodc]=false;
        q.pop_front();
        for(auto x:lista[nodc])
        {
            int vecin=x.first;
            int cost=x.second;
            if(d[nodc]+cost<d[vecin])
            {
                d[vecin]=d[nodc]+cost;
                if(!inq[vecin])
                {
                    q.push_back(vecin);
                    inq[vecin]=true;
                }
            }
        }
    }
    for(int i=2;i<=n;i++)
        out<<d[i]<<' ';
}
int main()
{
    citire();
    bellman(1);
    return 0;
}