Pagini recente » Cod sursa (job #2705071) | Cod sursa (job #3125868) | Cod sursa (job #2755919) | Cod sursa (job #1993174) | Cod sursa (job #2365231)
#include <fstream>
#include <queue>
#include <vector>
#define NMAX 50003
#define INF 500000000
using namespace std;
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");
struct varf{int x,c;};
int cmin[NMAX]; ///cmin[x]=costul drumului minim de la start la x
int nr[NMAX]; ///de cate ori a fost acualizat drumul minim de la start la x
queue<int> C;
vector<varf> G[NMAX];
bool bellman_ford();
void citire();
int start=1,n,m;
int main ()
{int i;
citire();
if(!bellman_ford())
fout<<"Ciclu negativ!";
else
for(i=2;i<=n;i++)
if(cmin[i]==INF) fout<<INF<<' ';
else
fout<<cmin[i]<<' ';
return 0;
}
void citire()
{
int i,j,c,k; varf aux;
fin>>n>>m;
for(k=0;k<m;k++)
{
fin>>i>>j>>c;
aux.x=j; aux.c=c;
G[i].push_back(aux);
}
}
bool bellman_ford()
///returnam 0 daca nu exista solutie
///returnam 1 daca exista solutie
{
int i,vf;
///initializare
for(i=1;i<=n;i++) cmin[i]=INF;
cmin[start]=0;
C.push(start);
while(!C.empty())
{
vf=C.front();
C.pop();
///parcurg lista de adiacenta a lui x
for(i=0;i<G[vf].size();i++)
if(cmin[G[vf][i].x]>cmin[vf]+G[vf][i].c)
{
cmin[G[vf][i].x]=cmin[vf]+G[vf][i].c;
nr[G[vf][i].x]++;
if(nr[G[vf][i].x]==n) return 0;
C.push(G[vf][i].x);
}
}
return 1;
}