Cod sursa(job #2123321)

Utilizator KOzarmOvidiu Badea KOzarm Data 6 februarie 2018 09:26:07
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.26 kb
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");


struct drum
{
    int y,c;
}el;

bool viz[50005];
int ok[50005],treceri[50005];
int n,m,x,y,c;


vector <drum> G[50002];
queue <int> q;




bool bfs()
{
    q.push(1);
    int poz;
    while(!q.empty())
    {
        poz=q.front();
        q.pop();
        viz[poz]=0;
        for(vector <drum>::iterator it=G[poz].begin();it!=G[poz].end();it++)
        {
            if(it->c+ok[poz]<ok[it->y])
            {
                ok[it->y]=it->c+ok[poz];
                treceri[it->y]++;
                if(treceri[it->y]==n)
                    return 1;
                if(!viz[it->y])
                {
                    viz[it->y]=1;
                    q.push(it->y);
                }
            }
        }
    }
    return 0;
}





int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y>>c;
        el.c=c;
        el.y=y;
        G[x].push_back(el);
    }
    for(int i=2;i<=n;i++)
        ok[i]=(1<<30);
    if(bfs())
        fout<<"Ciclu negativ!";
    else
        for(int i=2;i<=n;i++)
            fout<<ok[i]<<" ";
    return 0;
}