Cod sursa(job #412066)

Utilizator cosmin79Carabet Cosmin Andrei cosmin79 Data 5 martie 2010 12:33:27
Problema Ciclu hamiltonian de cost minim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.17 kb
#include <stdio.h>
#include <vector>
#define NMAX 20
#define LMAX 1<<18
#define INF 2000000000
#define pb push_back
using namespace std;
int n,m,C[NMAX][NMAX],k,rez=INF;
vector <int> A[NMAX],B[NMAX];
int best[LMAX][NMAX];
void read()
{
	scanf("%d%d",&n,&m);
	int i,x,y,z;
	k=(1<<n)-1;
	for (i=1; i<=m; i++)
	{
		scanf("%d%d%d",&x,&y,&z);
		A[x].pb(y);
		B[y].pb(x);
		C[x][y]=z;
	}
}
void init()
{
	int i,j;
	for (i=0; i<=k; i++)
		for (j=0; j<n; j++)
			best[i][j]=INF;
}
inline int min(int x,int y)
{
	return x<y ? x : y;
}
void solve()
{
	best[1][0]=0;
	int i,j,t,vec;
	for (i=1; i<=k; i++)
		for (j=0; j<n; j++)
			if (i & 1<<j)
				for (t=0; t<A[j].size(); t++)
				{
					vec=A[j][t];
					if (!(i & (1<<vec)))
						best[i^(1<<vec)][vec]=min(best[i^(1<<vec)][vec],best[i][j]+C[j][vec]);
				}
	for (i=0; i<B[0].size(); i++)
	{
		vec=B[0][i];
		if (best[k][vec]+C[vec][0]<rez)
			rez=best[k][vec]+C[vec][0];
	}
}
int main()
{
	freopen("hamilton.in","r",stdin);
	freopen("hamilton.out","w",stdout);
	read();
	init();
	solve();
	if (rez==INF)
	{
		printf("Nu exista solutie");
		return 0;
	}
	printf("%d\n",rez);
	return 0;
}