// node.cc/* -------------------------------------------------------------------gpc++ - The Genetic Programming KernelThis program is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation; either version 1, or (at your option)any later version.This program is distributed in the hope that it will be useful, butWITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNUGeneral Public License for more details.You should have received a copy of the GNU General Public Licensealong with this program; if not, write to the Free SoftwareFoundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.Copyright 1993, 1994 Adam P. Fraser and 1996, 1997 Thomas WeinbrennerFor comments, improvements, additions (or even money) contact:Thomas WeinbrennerGrauensteinstr. 2635789 LaimbachGermanyE-mail: thomasw@emk.e-technik.th-darmstadt.deWWW:    http://www.emk.e-technik.th-darmstadt/~thomasw  or (Address may be out of date)Adam Fraser, Postgraduate Section, Dept of Elec & Elec Eng,Maxwell Building, University Of Salford, Salford, M5 4WT, United Kingdom.E-mail: a.fraser@eee.salford.ac.ukTel:    (UK) 061 745 5000 x3633Fax:    (UK) 061 745 5999------------------------------------------------------------------- */// Function and Terminal Sets// The class NodeSet contains nodes, e.g. functions and terminals.// Some functions choose from either functions and terminals.  A quick// and fast access is desirable.  We do this by placing functions at// the beginning of the container, terminals at the end.#include <stdlib.h>#include <string.h>#include "gp.h"// Copy ConstructorGPNode::GPNode (const GPNode& gpo) : GPObject(gpo) {  nodeValue=gpo.nodeValue;   numOfArgs=gpo.numOfArgs;   representation=copyString (gpo.representation);}// Duplicate a stringchar *GPNode::copyString (char *str){  char *s=new char[strlen (str)+1];  strcpy (s, str);  return s;}// Load operationchar* GPNode::load (istream& is){  char line[400];  is >> nodeValue;  is >> numOfArgs;  // Read in string  do     {      if (!is)	return "Character '\"' not found in stream";      is >> line[0];    }  while (line[0]!='"');  int ix=0;  do     {      if (!is)	return "Matching character '\"' not found in stream";      is >> line[ix++];      if (ix>=(int)sizeof(line)) 	return "Internal buffer overflow: matching character '\"' not found";    }  while (line[ix-1]!='"');  line[ix-1]='\0';  if (representation)    delete [] representation;  representation=copyString (line);  return NULL;}// Save operationvoid GPNode::save (ostream& os){  os << nodeValue << ' ';  os << numOfArgs << ' ';  os << "\"" << representation << "\" ";}// We inherit this function because the user must not put anything in// our container by hand.void GPNodeSet::put (int, GPObject&){  GPExitSystem ("GPNodeSet::put", 		"User must not use this function, but putNode() instead."); }// Put a node in the container.  void GPNodeSet::putNode (GPNode& gpo){#if GPINTERNALCHECK  // Check if full  if (numFunctions+numTerminals==containerSize())    GPExitSystem ("GPNodeSet::putNode", "Node set is full");   // Check if node with same identification number is already in set  // (that's forbidden!)  if (searchForNode (gpo.value()))    GPExitSystem ("GPNodeSet::putNode", 		  "Node with same ID is not allowed in one node set");#endif  // Put functions at the beginning, terminals at the end.  if (gpo.isFunction())    GPContainer::put (numFunctions++, gpo);  else    GPContainer::put (containerSize() - (++numTerminals), gpo);}// Choose a node at random from node set with the given number of// argumentsGPNode* GPNodeSet::chooseNodeWithArgs (int args){  int i, num;  GPNode *n;  // First we count all nodes that have the specified number of  // arguments  for (i=0, num=0; i<containerSize(); i++)    if ((n=NthNode (i)))      if (n->arguments()==args)	num++;  // No node with given number of arguments?  if (num==0)    return NULL;  // Choose one  int k=GPrand() % num;  // Return the node with chosen index  for (i=0, num=0; i<containerSize(); i++)    if ((n=NthNode (i)))      if (n->arguments()==args)	if (num++==k)	  return n;#if GPINTERNALCHECK  GPExitSystem ("GPNodeSet::chooseNodeWithArgs", "Internal error"); #endif  // Avoid compiler warnings (this code is never reached)  return NULL;}// This chooses a function from the set.GPNode& GPNodeSet::chooseFunction (){#if GPINTERNALCHECK  if (numFunctions==0)    GPExitSystem ("GPNodeSet::chooseFunction", 		  "No function to choose from"); #endif  return *NthNode (GPrand() % numFunctions);}// This chooses a terminal from the set.GPNode& GPNodeSet::chooseTerminal (){#if GPINTERNALCHECK  if (numTerminals==0)    GPExitSystem ("GPNodeSet::chooseTerminal", 		  "No terminal to choose from"); #endif  return *NthNode (containerSize()-numTerminals+GPrand() % numTerminals);}// Prints out complete node set.  Functions are printed with// parenthesis and a value to indicate their number of argumentsvoid GPNodeSet::printOn (ostream& os){  // Move through the set printing out each node in turn  for (int i=0; i<containerSize(); i++)    {      GPNode* current=NthNode (i);      if (i>0)	os << ' ';      if (current)	{	  os << *current;	  if (current->isFunction())	    os << "(" << current->arguments() << ")";	}      else	os << "NoNode";    }}// Move through the set looking for the corresponding value.  Return// NULL, if no one found, otherwise the address of the nodeGPNode* GPNodeSet::searchForNode (int value){  // Move through the container  for (int n=0; n<containerSize(); n++)    {      GPNode* current=NthNode (n);      if (current)	if (current->value ()==value)	  return current;    }  // Not found  return NULL;}// Load operationchar* GPNodeSet::load (istream& is){  is >> numFunctions;  is >> numTerminals;  // Load container  return GPContainer::load (is);}// Save operationvoid GPNodeSet::save (ostream& os){  os << numFunctions << ' ';  os << numTerminals << ' ';  // Save container  GPContainer::save (os);}// Prints out complete node set for each adf treevoid GPAdfNodeSet::printOn (ostream& os){  // Move through container printing out each function set in turn  for (int i=0; i<containerSize(); i++)    {      GPNodeSet* current=NthNodeSet (i);      if (current)	os << "GP tree " << i << ": "  << *current << endl;      else	os << "No Set";    }}