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Cod sursa(job #412362)
#include<fstream>
#include<queue>
using namespace std;
#define nmax 50005
#define inf 1<<20
vector< pair<int,int> > g[nmax];
queue<int> q;
int d[nmax],viz[nmax];
int n,m;
typedef struct { int a;int b;int c; } muchie;
muchie e[250005];
void citire ()
{
ifstream fin ("bellmanford.in");
fin>>n>>m;
int i,a,b,c;
for(i=1;i<=m;i++)
fin>>a>>b>>c,g[a].push_back(make_pair(b,c)),e[i].a=a,e[i].b=b,e[i].c=c;
fin.close();
}
void bell (int nod)
{
int i,x,inc,sf;
for(i=1;i<=n;i++)
d[i]=inf;
q.push(nod);
d[nod]=0;inc=sf=0;
while(inc<=sf)
{
x=q.front();
viz[x]=0;
inc++;
q.pop();
for(i=0;i<g[x].size();i++)
if(d[g[x][i].first]>d[x]+g[x][i].second)
{
d[g[x][i].first]=d[x]+g[x][i].second;
if(!viz[g[x][i].first])
{
q.push(g[x][i].first);
sf++;
viz[g[x][i].first]=1;
}
}
}
}
long check_negativ()
{
long i;
for(i=1; i<=m; i++)
if(d[e[i].a]+e[i].c<d[e[i].b])
return 1;
return 0;
}
void scrie ()
{
int i;
ofstream fout("bellmanford.out");
if(check_negativ())
fout<<"Ciclu negativ";
else
for(i=2;i<=n;i++)
fout<<d[i]<<' ';
fout.close();
}
int main ()
{
citire();
bell(1);
scrie();
return 0;
}