Cod sursa(job #414970)

Utilizator al_flAlexandru Flavian al_fl Data 10 martie 2010 19:32:07
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.9 kb
#include<fstream>
#include<queue>
#include<vector>
using namespace std;
#define nmax 50005
#define inf 1<<30
vector<int> g[nmax],c[nmax];
queue<int> q;
int d[nmax],cost[nmax];
int n,m;
void citire ()
{
	ifstream fin("bellmanford.in");
	int i,a,b,cost;
	fin>>n>>m;
	for(i=1;i<=m;i++)
		fin>>a>>b>>cost,g[a].push_back(b),c[a].push_back(cost);
	fin.close ();
}
int bell ( int nod )
{
	int i,x,a,b;
	for(i=1;i<=n;i++)
		d[i]=inf;
	d[nod]=0;
	q.push(nod);
	while(!q.empty())
	{
		x=q.front();
		q.pop();
		for(i=0;i<g[x].size();i++)
		{
			a=g[x][i],b=c[x][i];
			if(d[a]>d[x]+b)
			{
				d[a]=d[x]+b,q.push(a);
				cost[a]++;
				if(cost[a]>n-1)
					return 0;
			}
		}
	}
	return 1;
}
int main ()
{
	citire ();
	int i;
	ofstream fout("bellmanford.out");
	if(bell(1)==0)
		fout<<"Ciclu negativ!";
	else
		for(i=2;i<=n;i++)
			fout<<d[i]<<' ';
	fout.close ();
	return 0;
}