// LongCal.cpp: implementation of the CLongCal class.
//
//  created by darnshong in ioe cas.
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "afx.h"
#include "LongCal.h"

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CLongCal::CLongCal()
{
		this->m_str="0";
		this->m_sign='+';

}
CLongCal::CLongCal(CString str)
{
	if(str.IsEmpty())
	{
		this->m_str="0";
		this->m_sign='+';
		return;
	}
	else
	{
		if(str[0]=='+')
		{
			this->m_sign='+';
			this->m_str=str.Right(str.GetLength()-1);
			
		}
		else if(str[0]=='-')
		{
			this->m_sign='-';
			this->m_str=str.Right(str.GetLength()-1);
		}
		else if(isNum(str[0]))
		{
			this->m_sign='+';
			this->m_str=str;
		}
		else
		{
			this->m_sign='+';
			m_str="0";
			return;
		}
		trimNoNum(m_str);
		trimZero(m_str);
		m_str.MakeReverse();


	}
  
}

CLongCal::~CLongCal()
{

}

bool CLongCal::isNum(char a)
{
  if(a>=48 && a<=57)
	  return true;
  else 
	  return false;
}

void CLongCal::Add(CLongCal c)
{   

	if(this->m_sign=='+' && c.m_sign=='+')
	{
      this->m_str=this->aADDb(this->m_str,c.m_str);
	  this->m_sign='+';

	}
	else if(this->m_sign=='-' && c.m_sign=='-')
	{
      this->m_str=this->aADDb(this->m_str,c.m_str);
	  this->m_sign='-';

	}
	else if(this->m_sign=='+' &&c.m_sign=='-')
	{
		int iComp=strValueCompare(this->m_str,c.m_str);
		if(iComp==0)
		{
			this->m_sign='+';
			this->m_str="0";
		}
		else if(iComp==1)
		{
			this->m_str=aSUBb(this->m_str,c.m_str);
			this->m_sign='+';
		}
		else //iComp=-1
		{
			
			this->m_str=aSUBb(c.m_str,this->m_str);
			this->m_sign='-';


		}

	}
	else // this->m_sign=='-' &&c.m_sign=='+'
	{
		int iComp=strValueCompare(this->m_str,c.m_str);
		if(iComp==0)
		{
			this->m_sign='+';
			this->m_str="0";
		}
		else if(iComp==-1)
		{
			this->m_str=aSUBb(c.m_str,this->m_str);
			this->m_sign='+';
		}
		else //iComp=1
		{
			this->m_str=aSUBb(this->m_str,c.m_str);
			this->m_sign='-';


		}

	}
	

}

void CLongCal::swapString(CString &a, CString &b)
{
  CString str;
  str=a;
  a=b;b=str;
}

CString CLongCal::aADDb(CString a, CString b)
{
	int tLen=a.GetLength()>=b.GetLength()?a.GetLength():b.GetLength();
    int carry=0;
	CString temp('0',tLen);
	 int ia,ib;
	 for(int i=0;i<tLen;i++)
	  {
		  ia=strGetChar(a,i);
		  ib=strGetChar(b,i);
		  ia+=ib;
		  ia+=carry;
		  if(ia>=10)
		  {
			  ia-=10;
			  carry=1;
		  }
		  else
		  {
			  carry=0;
		  }
		  temp.SetAt(i,ia+'0');

	  }
	  
	  
	  if(carry==1)
		  temp+="1";
	  
	  return temp;
		


}

void CLongCal::trimZero(CString &str)
{
	int iCount=0;
	while( iCount<(str.GetLength()) && str[iCount]=='0' )
		iCount++;
	str=str.Right(str.GetLength()-iCount);
	if(str.IsEmpty())
		str="0";

}

void CLongCal::trimNoNum(CString &str)
{
	int iCount=0;
		while(iCount<str.GetLength() && isNum(str[iCount]))
			iCount++;
		str=str.Left(iCount);
		if(str.IsEmpty())
			str="0";

}

CString CLongCal::aSUBb(CString a, CString b)
{
	int tLen=a.GetLength()>=b.GetLength()?a.GetLength():b.GetLength();
    int carry=0;
	CString temp('0',tLen);
	 int ia,ib;
	 for(int i=0;i<tLen;i++)
	  {
		  ia=strGetChar(a,i);
		  ib=strGetChar(b,i);
		  ia-=ib;
		  ia+=carry;
		  if(ia<0)
		  {
			  ia+=10;
			  carry=-1;
		  }
		  else
		  {
			  carry=0;
		  }
		  temp.SetAt(i,ia+'0');

	  }
	  
	   temp.MakeReverse();
	   trimZero(temp);
	   temp.MakeReverse();
      return temp;

}

int CLongCal::strValueCompare(CString a, CString b)
{
	if(a.Compare(b)==0) return 0;
	a.MakeReverse();
	b.MakeReverse();
	if(a.GetLength()<b.GetLength() || (a.GetLength()==b.GetLength() &&a.Compare(b)==-1))
	{ 
		return -1;
	}
	else
	{ 
		return 1;
	}

}

void CLongCal::iniUseString(CString str)
{
	if(str.IsEmpty())
	{
		this->m_str="0";
		this->m_sign='+';
		return;
	}
	else
	{
		if(str[0]=='+')
		{
			this->m_sign='+';
			m_str=str.Right(str.GetLength()-1);
			
		}
		else if(str[0]=='-')
		{
			this->m_sign='-';
			m_str=str.Right(str.GetLength()-1);
		}
		else if(isNum(str[0]))
		{
			this->m_sign='+';
			this->m_str=str;
		}
		else
		{
			this->m_sign='+';
			m_str="0";
			return;
		}
		trimNoNum(m_str);
		trimZero(m_str);
		m_str.MakeReverse();


	}

}

bool CLongCal::isZero()
{
 if(this->m_str.Compare("0")==0)
	 return true;
 else 
	 return false;
}

void CLongCal::toString()
{
  CString temp=this->m_str;
  temp.MakeReverse();
  trimZero(temp);
  temp.TrimLeft();
  if(this->m_sign=='-')
	  temp="-"+temp;
  printf("\n計算結果為：%s",temp.LockBuffer());
  temp.ReleaseBuffer();
}

int CLongCal::strGetChar(CString a ,int index)
{
 
  int nLen=a.GetLength();
  if(index>nLen-1)
  {
	  return 0;
  }
  else
  {
	  return a[index]-'0';
  }

}