Cod sursa(job #2718578)

Utilizator Dex9186Darius Turcu Dex9186 Data 8 martie 2021 20:24:33
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.39 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
using namespace std;
ifstream fi("bellmanford.in");
ofstream fo("bellmanford.out");
int n,m,i,j,k,d[50001],nrap[50001],c;
#define inf 1<<29
vector<pair<int,int>>v[50001];
queue<int>q;
bool fv[50001],neg;

void bf(bool &neg)
{
    int i,x,nod,c;
    size_t j;
    neg=false;
    for(i=1;i<=n;i++)
    {
        d[i]=inf;
    }
    d[1]=0;
    q.push(1);
    fv[1]=true;
    while(!q.empty() && !neg)
    {
        x=q.front();
        q.pop();
        fv[x]=false;
        for(j=0;j<v[x].size();j++)
        {
            nod=v[x][j].first;
            c=v[x][j].second;
            if(d[nod]>d[x]+c)
            {
                d[nod]=d[x]+c;
                if(!fv[nod])
                {
                    if(nrap[nod]>n)
                        neg=true;
                    else
                    {
                        q.push(nod);
                        fv[nod]=false;
                        nrap[nod]++;
                    }
                }
            }
        }
    }
}
int main()
{
    fi>>n>>m;
    for(k=1;k<=m;k++)
    {
        fi>>i>>j>>c;
        v[i].push_back(make_pair(j,c));
    }
    bf(neg);
    if(neg)
        fo<<"Ciclu negativ!";
    else
    {
        for(i=2;i<=n;i++)
        {
            fo<<d[i]<<" ";
        }
    }
    return 0;
}