Pagini recente » Cod sursa (job #773944) | Cod sursa (job #202052) | Cod sursa (job #214980) | Cod sursa (job #311831) | Cod sursa (job #2268445)
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");
const int NMax = 50000;
const int oo = 1000000000;
int N,M,D[NMax+5];
vector < pair <int, int> > G[NMax+5];
queue <int> Q;
bool InQ[NMax + 5],Ok;
int NrQ[NMax + 5];
void Read()
{
fin>>N>>M;
for(int i = 1; i <= M ; ++i)
{
int x,y,c;
fin>>x>>y>>c;
G[x].push_back(make_pair(y,c));
}
}
int BellmanFord()
{
for(int i = 2; i <= N; ++i)
D[i] = oo;
Q.push(1);InQ[1] = 1; NrQ[1]++;
Ok = 1;
while(!Q.empty() && Ok)
{
int Nod = Q.front(); Q.pop();InQ[Nod] = 0;
for(auto i : G[Nod])
{
int Vecin = i.first, Cost = i.second;
if(D[Vecin] > D[Nod] + Cost)
{
D[Vecin] = D[Nod] + Cost;
if(InQ[Vecin] == 0)
{
Q.push(Vecin);
InQ[Vecin] = 1;
NrQ[Vecin]++;
if(NrQ[Vecin] > N)
Ok = 0;
}
}
}
}
return Ok;
}
void Print()
{
for(int i = 2; i <= N ; ++i)
fout<<D[i]<<" ";
fout<<"\n";
}
int main()
{
Read();
if(BellmanFord()==0)
fout<<"Ciclu negativ!\n";
else
Print();
return 0;
}