大整数类加法与乘法

bigInt = "+0";
}
}
}
else
bigInt = "+0";
}
// 复制构造函数
inline CBigInt::CBigInt(const CBigInt &value) : bigInt(value.bigInt)
{}
inline CBigInt::CBigInt(int num) பைடு நூலகம்
};
/************************************************************************/
/* 构造函数
/************************************************************************/
{
if (bigInt.size() > 0)
{
if (bigInt[0] != '+' && bigInt[0] != '-')
{
string::size_type i = 0;
// 去除多余的0
for (; i < bigInt.size() - 1 && bigInt[i] == '0'; i++);
else
bigInt.insert((string::size_type)0, 1, '+');
}
else
{
if (bigInt.size() == 1)
bigInt = "+0";
else
{
string::size_type j = 1;
// 处理特殊情况“-0”
if (bigInt == "-0")
bigInt = "+0";
}
}
}
else
bigInt = "+0";
}
inline bool operator == (const CBigInt &lValue, const CBigInt &rValue)
{
return !(lValue < rValue);
}
inline CBigInt& CBigInt::operator = (const CBigInt &value)
{
bigInt = value.bigInt;
return *this;
}
// unsigned ==
if (i > 0)
bigInt.replace((string::size_type)0, i, "+");
else
bigInt.insert((string::size_type)0, 1, '+');
}
else
{
if (bigInt.size() == 0)
friend bool operator < (const CBigInt &lValue, const CBigInt &rValue)
{
if (lValue.bigInt[0] != rValue.bigInt[0])
{
// '+'ASCII码为43，'-'ASCII码为45
return lValue.bigInt[0] > rValue.bigInt[0];
}
else
{
if (lValue.bigInt[0] == '+')
return lValue.smaller(rValue.bigInt); // 正数的情况
else
{
if (bigInt.size() == value.size())
return bigInt.substr(1) > value.substr(1);
return lValue.greater(rValue.bigInt); // 负数的情况
}
}
friend bool operator > (const CBigInt &lValue, const CBigInt &rValue)
{
if (lValue.bigInt[0] != rValue.bigInt[0])
inline bool CBigInt::equal(const string &value) const
{
return bigInt.substr(1) == value.substr(1);
}
// unsigned <
inline bool CBigInt::smaller(const string &value) const
{
if (bigInt.size() == value.size())
return bigInt.substr(1) < value.substr(1);
else
return bigInt.size() < value.size();
}
// unsigned >
inline bool CBigInt::greater(const string &value) const
{
return lValue.bigInt == rValue.bigInt;
}
inline bool operator != (const CBigInt &lValue, const CBigInt &rValue)
{
return !(lValue.bigInt == rValue.bigInt);
// 去掉多余的0
for (; j < bigInt.size() - 1 && bigInt[j] == '0'; j++);
if (j > 1)
bigInt.erase((string::size_type)1, j - 1);
if (bigInt == "-0")
CBigInt operator ++ (int);
// postfix decrement
CBigInt operator -- (int);
private:
// unsigned +=
void plus(const string &);
// unsigned -=
void minus(const string &);
bigInt = "+0";
else
{
string::size_type j = 1;
for (; j < bigInt.size() - 1 && bigInt[j] == '0'; j++);
if (j > 1)
bigInt.erase((string::size_type)1, j - 1);
}
inline bool operator <= (const CBigInt &lValue, const CBigInt &rValue)
{
return !(lValue > rValue);
}
inline bool operator >= (const CBigInt &lValue, const CBigInt &rValue)
{
if (num == 0)
bigInt = "+0";
else if (num > 0)
bigInt = '+';
else
{
bigInt = '-';
num *= -1;
}
string temp = "";
while (num != 0)
{
return lValue.bigInt[0] < rValue.bigInt[0];
else
{
if (lValue.bigInt[0] == '+')
return lValue.greater(rValue.bigInt);
else
return lValue.smaller(rValue.bigInt);
temp += num % 10 + '0';
num = num / 10;
}
for (int i = temp.size() - 1; i >= 0; i--)
bigInt += temp[i];
}
inline CBigInt::CBigInt(const char *str) : bigInt(str)
CBigInt& operator += (const CBigInt &);
CBigInt& operator -= (const CBigInt &);