Cod sursa(job #521182)

Utilizator unknownliviuMaria Liviu Valentin unknownliviu Data 11 ianuarie 2011 16:47:44
Problema Algoritmul Bellman-Ford Scor 35
Compilator cpp Status done
Runda Arhiva educationala Marime 0.96 kb
#include<vector>
#include<fstream>
using namespace std;
ifstream in("bellmanford.in");
ofstream out("bellmanford.out");
const int N=50050;
const int INF=10000000;
vector<int>a[N],c[N];
bool inc[N];
int n,m;
void read()
{
	int x,y,z;
	in>>n>>m;
	for(int i=1;i<=m;i++)
	{
		in>>x>>y>>z;
		a[x].push_back(y);
		c[x].push_back(z);
	}
}
int coada[N],d[N],q[N];
bool bf()
{
	bool bn=1;
	for(int i=1;i<=n;i++)
		d[i]=INF;
	int x,cost,p,u,r;
	p=u=0;
	d[1]=0;
	coada[0] = 1;
	inc[1] = true;
	while(p<=u && bn)
	{
		r=coada[p++];
		inc[r] = false;
		for(int i=0;i<a[r].size();i++)
		{
			x = a[r][i];
			cost = c[r][i];
			if(d[r]+cost < d[x])
			{
				d[x] = d[r]+cost;
				if(!inc[x])
				{
					inc[x] = true;
					q[x]++;
					if(q[x]>n-1)
						bn=false;
					coada[++u] = x;
				}
			}
		}
	}
	return bn;
}
int main()
{
	read();
	if(bf())
		for(int i=2;i<=n;i++)
			out<<d[i]<<" ";
	else
		out<<"Ciclu negativ!";
	return 0;
}