Cod sursa(job #2356479)

Utilizator BiancaMariaVulsanVulsan Bianca Maria BiancaMariaVulsan Data 26 februarie 2019 18:31:22
Problema Algoritmul Bellman-Ford Scor 5
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.25 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#define nmax 50005
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
int n,m, s[nmax], d[nmax];
vector <pair<int,int> > v[nmax];
queue <int> q;

void citire()
{
    int i,x,y,c;
    f>>n>>m;
    for(i=1; i<=m; i++)
    {
        f>>x>>y>>c;
        v[x].push_back({y,c});
    }
}

void afis()
{
    int i,j;
    for(i=1; i<=n; i++)
    {for(j=0; j<v[i].size(); j++)
            cout<< v[i][j].first <<" ";
    cout<<endl;}
}

int bellman()
{
    int nod, next, cst,i;
    for(i=2; i<=n; i++)
        d[i]=1e9;
    q.push(1);
    s[1]=1;
    while(!q.empty())
    {
        nod=q.front();
        s[nod]=0; //nu mai e in coada
        q.pop();
        for(i=0; i<v[nod].size(); i++)
        {
            next=v[nod][i].first;
            cst=v[nod][i].second;
            if(cst+d[nod]<d[next] && s[next]==0)
                {d[next]=d[nod]+cst; q.push(next); s[next]=1;}
        }
    }
    return 1;
}

int main()
{
    citire();
    //afis();
    if(bellman())
        for(int  i=2; i<=n; i++)
        g<<d[i]<<" ";
    else
        g<<"Ciclu negativ!";
    f.close();
    g.close();
    return 0;
}