Cod sursa(job #435250)
/*
* File: main.cpp
* Author: SpeeDemon
*
* Created on April 7, 2010, 9:04 AM
*/
#include <queue>
#include <cstdlib>
#include <fstream>
#include <iterator>
#define oo 0x3f3f3f3f
/*
*
*/
using namespace std;
typedef pair< int, int > pr;
queue< int > Q;
vector< int > d, howmuch;
vector< bool > inQ;
vector< vector< pr > > G;
vector< pr >::const_iterator it, iend;
int main(int argc, char** argv)
{
int N, M, x, y, c;
ifstream in( "bellmanford.in" );
in>>N>>M;
G.resize(N);
for( ; M; --M )
{
in>>x>>y>>c;
--x, --y;
G[x].push_back( pr( y, c ) );
}
d.resize( N );
inQ.resize( N );
howmuch.resize( N );
for( Q.push(0); !Q.empty(); )
{
x=Q.front(); Q.pop();
inQ[x]=false;
for( it=G[x].begin(), iend=G[x].end(); it < iend; ++it )
{
y=it->first, c=it->second;
if( !howmuch[y] )
{
d[y]=d[x]+c;
Q.push( y );
inQ[y]=true;
++howmuch[y];
continue;
}
if( d[y] > d[x]+c )
{
d[y]=d[x]+c;
if( !inQ[y] )
{
Q.push(y);
inQ[y]=true;
++howmuch[y];
if( howmuch[y] > N )
{
ofstream out( "bellmanford.out" );
out<<"Ciclu negativ!\n";
return EXIT_SUCCESS;
}
}
}
}
}
ofstream out( "bellmanford.out" );
copy( d.begin()+1, d.end(), ostream_iterator<int>( out, " " ) );
out<<'\n';
return (EXIT_SUCCESS);
}