Mai intai trebuie sa te autentifici.
Cod sursa(job #1126220)
Utilizator | Data | 26 februarie 2014 22:03:23 | |
---|---|---|---|
Problema | Algoritmul Bellman-Ford | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 1.21 kb |
#include <fstream>
#include <vector>
#include <queue>
#define IN "bellmanford.in"
#define OUT "bellmanford.out"
#define NMAX 50005
#define INT_MAX 0x3f3f3f3f
using namespace std;
ifstream in(IN);
ofstream out(OUT);
vector < pair<int, int> > G[NMAX];
queue <int> Q;
bool InQueue[NMAX], NrViz[NMAX], CicluNegativ;
int n, m, dmin[NMAX];
int main()
{
int i, a, b, c, nod, len;
in>>n>>m;
for(i=1; i<=m; ++i)
{
in>>a>>b>>c;
G[a].push_back(make_pair(b, c));
}
//for(i=1; i<=n; ++i)
//dmin[i]=INT_MAX;
memset(dmin ,INT_MAX ,sizeof(dmin));
Q.push(1);
dmin[1]=false;
while(!Q.empty() && !CicluNegativ)
{
nod=Q.front();
Q.pop();
InQueue[nod]=false;
len=G[nod].size();
for(i=0; i<len; ++i)
if(dmin[nod]+G[nod][i].second < dmin[G[nod][i].first])
{
dmin[G[nod][i].first] = dmin[nod] + G[nod][i].second;
if(!InQueue[G[nod][i].first])
{
Q.push(G[nod][i].first);
++NrViz[G[nod][i].first];
}
if(NrViz[G[nod][i].first]>=n)
{
CicluNegativ=true;
break;
}
}
}
if(CicluNegativ)
out<<"Ciclu negativ!";
else
for(i=2; i<=n; ++i)
out<<dmin[i]<<' ';
out<<'\n';
in.close();
out.close();
return 0;
}