Cod sursa(job #1455901)

Utilizator Liviu98Dinca Liviu Liviu98 Data 29 iunie 2015 13:27:29
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.41 kb
#include <iostream>
#include <fstream>
#include <stdio.h>
#include <vector>
#include <cstring>
#include <deque>
#define NMax 50010
using namespace std;
const long long int INFINIT=99999999999;
long N,M,x,y,z,D[NMax],C[NMax];
bool Ciclu=false;
vector<pair<int,int> > Graf[NMax];
deque<int> Q;

void Read()
{
    freopen("bellmanford.in","r",stdin);
    scanf("%d%d",&N,&M);
    for(int i=1;i<=M;i++)
    {
        scanf("%d%d%d",&x,&y,&z);
        Graf[x].push_back(make_pair(y,z));
    }
}

void BellManFord(const int &NodStart)
{
    Q.push_back(NodStart);
    for(int i=0;i<=N;i++)
        D[i]=INFINIT;
    D[1]=0;
    while(Q.empty()==false)
    {
        int nod=Q.front();
        Q.pop_front();
        for(int i=0;i<Graf[nod].size() && Ciclu==false;i++)
        {
            if(D[Graf[nod][i].first]>D[nod]+Graf[nod][i].second)
            {
                D[Graf[nod][i].first]=D[nod]+Graf[nod][i].second;
                Q.push_back(Graf[nod][i].first);
                C[Graf[nod][i].first]++;
                if(C[Graf[nod][i].first]>N)
                    Ciclu=true;
            }
        }
    }
}

void Write()
{
    freopen("bellmanford.out","w",stdout);
    BellManFord(1);
    if(Ciclu==false)
    {
        for(int i=2;i<=N;i++)
            printf("%d ",D[i]);
    }
    else
        printf("Ciclu negativ!");
}

int main()
{
    Read();
    Write();
}