Cod sursa(job #460956)
#include <cstdlib>
#include <fstream>
#define Nmax 19
#define Mmax 524288
#define oo 1000000000
/*
*
*/
using namespace std;
int d[Nmax], dd[Nmax];
int G[Nmax][Nmax], C[Nmax][Nmax], CC[Mmax][Nmax];
int main( void )
{
int N, M, x, y, x2, y2, z, s, till;
ifstream in( "hamilton.in" );
ofstream out( "hamilton.out" );
in>>N>>M;
for( x=0; x < N; ++x )
for( y=0; y < N; ++y )
C[x][y]=oo;
for( ; M; --M )
{
in>>x>>y;
in>>C[x][y];
G[y][++G[y][0]]=x;
++d[x]; ++dd[y];
}
for( x=0; x < N; ++x )
if( 0 == d[x]*dd[x] )
{
out<<"-1\n";
return EXIT_SUCCESS;
}
till=1<<N;
for( x=0; x < till; ++x )
for( y=0; y < N; ++y )
CC[x][y]=oo;
CC[1][0]=0;
for( x=0; x < till; ++x )
for( y=0, y2=1; y < N; ++y, y2<<=1 )
if( x & y2 )
for( x2=x^y2, z=1; z <= G[y][0]; ++z )
if( x & (1<<G[y][z]) )
CC[x][y]=min( CC[x][y], CC[x2][G[y][z]]+C[G[y][z]][y] );
for( s=oo, till-=1, x=1; x <= G[0][0]; ++x )
s=min( s, CC[till][G[0][x]]+C[G[0][x]][0] );
if( oo == s )
out<<"-1\n";
else out<<s<<'\n';
return EXIT_SUCCESS;
}