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Cod sursa(job #941596)
#include <fstream>
#include <vector>
#include <set>
#include <algorithm>
#define inf 0x3f3f3f3f
using namespace std;
ifstream in("bellmanford.in");
ofstream out("bellmanford.out");
struct muchie
{
int b, c;
} e;
long n, m, i, j, k, left, right, cost[50], f[50];
vector <muchie> v[50];
vector <pair<long, long> > h;
void init()
{
long i;
cost[1]=0;
for(i=2; i<=n; i++)
cost[i]=inf;
h.push_back(make_pair(0, 1));
make_heap(h.begin(), h.end());
}
void bellmanford()
{
pair<long, long> per;
long j, nod;
while(h.size())
{
pop_heap(h.begin(), h.end());
per=h.back();
h.pop_back();
nod = per.second;
f[nod]=0;
for(j=0; j<v[nod].size(); j++)
{
//e = v[nod][j];
if(cost[nod]+v[nod][j].c<cost[v[nod][j].b])
{
cost[v[nod][j].b]=cost[nod]+v[nod][j].c;
if(!f[v[nod][j].b])
{
f[v[nod][j].b]=1;
h.push_back(make_pair(cost[v[nod][j].b], v[nod][j].b));
push_heap(h.begin(), h.end());
}
}
}
}
}
long ciclu_negativ()
{
long i;
for(i=1; i<=n; i++)
for(int j=0;j<v[i].size();j++)
if(cost[i]+v[i][j].c<cost[v[i][j].b])
return 1;
return 0;
}
int main()
{
int x,y,c;
in>>n>>m;
for(i=1; i<=m; i++)
{
in>>x>>y>>c;
e.b = y;
e.c = c;
v[x].push_back(e);
}
init();
bellmanford();
if(ciclu_negativ())
{
out<<"Ciclu negativ!\n";
return 0;
}
for(i=2; i<=n; i++)
out<<cost[i]<<" ";
return 0;
}