calculator.cpp

穷举法进行三八二十四的计算。列举所有可能的表达式进行计算筛选。

// Calculator.cpp: implementation of the CCalculator class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "RepComb.h"
#include "Calculator.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
double CCalculator::sub(double a,double b)
{
	return a-b;
}
double CCalculator::product(double a,double b)
{
	return a*b;
}
double CCalculator::divide(double a,double b)
{
	if(b==0)return 0;
	return a/b;
}
char CCalculator::m_cOperatorTable[N]={'+','-','*','/','\0'};
char CCalculator::m_nPriorityL[N][N]={
	{-1,-1,1,1,-1},
	{-1,-1,1,1,-1},
	{-1,-1,-1,-1,-1},
	{-1,-1,-1,-1,-1},
	{-1,-1,-1,-1,-1}
};
char CCalculator::m_nPriorityR[N][N]={
	{1,1,1,1,-1},
	{-1,1,1,1,-1},
	{-1,-1,-1,1,-1},
	{-1,-1,-1,1,-1},
	{-1,-1,-1,-1,-1}
};

CCalculator::CCalculator()
{
	m_pfOperation[0]=this->add;
	m_pfOperation[1]=this->sub;
	m_pfOperation[2]=this->product;
	m_pfOperation[3]=this->divide;

}

CCalculator::~CCalculator()
{

}

double CCalculator::compute(double a, char op, double b)
{
  int n;
  for(n=0;n<N;n++)
	  if(m_cOperatorTable[n]==op)
		  break;
  if(n>N-1)
  {
	  m_nStatus=NOOPERATOR;
	  return -1;
  }
  m_nStatus=OK;
  return (this->*m_pfOperation[n])(a,b);
}
double CCalculator::add(double a,double b)
{
	return a+b;
}

//当c1出现在c2的右边时调用此函数比较
int CCalculator::compareR(char c1, char c2)
{
  int n1,n2;
  for(n1=0;n1<N;n1++)
	  if(m_cOperatorTable[n1]==c1) 
		  break;
  if(n1>N-1) return -2;
  for(n2=0;n2<N;n2++)
	  if(m_cOperatorTable[n2]==c2)
		  break;
  if(n2>N-1) return -2;
  return m_nPriorityR[n1][n2];
}
//当c1出现在c2左边时调用此函数比较
int CCalculator::compareL(char c1, char c2)
{
  int n1,n2;
  for(n1=0;n1<N;n1++)
	  if(m_cOperatorTable[n1]==c1) 
		  break;
  if(n1>N-1) return -2;
  for(n2=0;n2<N;n2++)
	  if(m_cOperatorTable[n2]==c2)
		  break;
  if(n2>N-1) return -2;
  return m_nPriorityL[n1][n2];
}