/* table_offset.cpp
 * Copyright (C) 2008, Francisco Claude, all rights reserved.
 *
 * Table for offsets.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */
 
 
#include "table_offset.h"


// Interface for old implementation
void genera(ushort * bch, uint u, ushort * F, uint lF);
uint generaClase(ushort * bch, uint u, uint clase, uint puestos, uint pos_ini, uint generado);
uint offset_func(uint u, uint busca);
uint offsetRecursivo(uint u, uint busca, uint clase, uint puestos, uint pos_ini, uint generado);
uint __indiceFunc;
uint __indAcumulado;
ushort * __Lis;
// End interface old implementation


table_offset::table_offset(uint u) {
	this->u = u;
	users_count = 0;
	short_bitmaps = new ushort[((1<<u)+1)];
	offset_class = new ushort[u+2];
	binomial = new uint*[u+1];
	log2binomial = new ushort*[u+1];
	for(uint i=0;i<u+1;i++) {
		binomial[i] = new uint[u+1];
		log2binomial[i] = new ushort[u+1];
		for(uint j=0;j<u+1;j++) {
			binomial[i][j] = 0;
			log2binomial[i][j] = 0;
		}
	}
	for(uint i=0;i<u+1;i++) {
		binomial[i][0] = 1;
		binomial[i][1] = 1;
		binomial[i][i] = 1;
		log2binomial[i][0] = 0;
		log2binomial[i][1] = 0;
		log2binomial[i][i] = 0;
	}
	for(uint j=1;j<u+1;j++) {
		for(uint i=j+1;i<u+1;i++) {
			binomial[i][j] = binomial[i-1][j-1]+binomial[i-1][j];
			log2binomial[i][j] = bits(binomial[i][j]-1);
		}
  }
	fill_tables();
}

void table_offset::fill_tables() {
	genera(short_bitmaps, u, offset_class, u);
	rev_offset = __Lis;
	//delete [] __Lis;
}

table_offset::~table_offset() {
	delete [] short_bitmaps;
	delete [] offset_class;
	for(uint i=0;i<u+1;i++) {
		delete [] binomial[i];
		delete [] log2binomial[i];
	}
	delete [] binomial;
	delete [] log2binomial;
	delete [] rev_offset;
}

uint table_offset::size() {
	uint ret = sizeof(ushort)*(((1<<u)+1)+u+1);
	ret += (sizeof(uint)+sizeof(ushort))*((u+1)*(u+1));
	ret += sizeof(ushort)*(2<<(u+1));
  ret += sizeof(ushort)*(u+2);
	return ret;
}

// OLD implementation, replace

void genera(ushort * bch, uint u, ushort * F, uint lF) {
    __indAcumulado=0;
    __indiceFunc=0;
    F[0]=0;
    __Lis = new ushort[(2<<(u+1))]; //(uint *)malloc((2<<u+1)*sizeof(uint));
    for (uint i=0;i<=u;i++) {
        __indAcumulado += generaClase(bch, u, i, 0, 0, 0);
        F[i+1] = __indiceFunc;
    }
}

uint generaClase(ushort * bch, uint u, uint clase, uint puestos, uint pos_ini, uint generado) {
    uint ret=0;
    if (clase==puestos) {
        bch[__indiceFunc] = generado;
        __Lis[generado] = __indiceFunc-__indAcumulado;
        __indiceFunc++;
        return 1;
    }
    if (clase<puestos)
        return 0;
    for (uint i=pos_ini;i<u;i++) {
        uint tmp = generado | (1<<i);
        ret += generaClase(bch, u, clase, puestos+1, i+1, tmp);
    }
    return ret;
}
