// * 重载
public static BigInteger operator *(BigInteger b1, BigInteger b2)
{
BigInteger b3 = new BigInteger();
BigInteger b11 = new BigInteger();
BigInteger b22 = new BigInteger();
for (int i = 0; i < b11.value.Length; i++)
{
b11.value[i] = b1.value[i];
b22.value[i] = b2.value[i];
}
if ((b11 == "0") || (b22 == "0")) //只要一个数为0，结果为0
{
b3.value[0] = '+';
for (int i = 1; i < b3.value.Length; i++)
b3.value[i] = '0';
}
else
{
for (int i = b11.value.Length - 1; i > 1; i--)
{
for (int j = 0; j < int.Parse(b11.value[i].ToString()); j++)
{
b3 += b22;
}
for (int i1 = 1; i1 < b11.value.Length - 1; i1++) //b22左移一位相当于乘以10
b22.value[i1] = b22.value[i1 + 1];
b22.value[b11.value.Length - 1] = '0';
}
}
if (((b1.value[0] == '+') && (b2.value[0] == '+')) || ((b1.value[0] == '-') && (b2.value[0] == '-'))) //同号为正
b3.value[0] = '+';
else //异号为负
b3.value[0] = '-';
b3.valuestr = b3.Value_to_Str();
return b3;
}
// + 重载
public static BigInteger operator +(BigInteger b1, BigInteger b2)
{
BigInteger b3 = new BigInteger();
BigInteger b11 = new BigInteger();
BigInteger b22 = new BigInteger();
BigInteger temp = new BigInteger();
for (int i = 0; i < b11.value.Length; i++)
{
b11.value[i] = b1.value[i];
b22.value[i] = b2.value[i];
}
int carry = 0;
if ((b1.value[0] == '+' && b2.value[0] == '+') || (b1.value[0] == '-' && b2.value[0] == '-')) //同号
{
for (int i = b1.value.Length - 1; i > 1; i--)
{
int n1 = int.Parse(b1.value[i].ToString());
int n2 = int.Parse(b2.value[i].ToString());
char[] a = ((n1 + n2 + carry) % 10).ToString().ToCharArray();
b3.value[i] = a[a.Length - 1];
if (n1 + n2 >= 10) //有进位
carry = 1;
else
carry = 0;
}
b3.value[0] = b1.value[0];
}
else //异号
{
b11.value[0] = '+';
b22.value[0] = '+';
if (b11 == b22)
{
b3.value[0] = '+';
for (int i = 1; i < b3.value.Length; i++)
b3.value[i] = '0';
}
else
{
if (b11 < b22) //b1的绝对值小于b2的绝对值
{
if (b1.value[0] == '+')
{
b3.value[0] = '-';
}
else
{
b3.value[0] = '+';
}
temp = b22;
b22 = b11;
b11 = temp;
}
else //b1的绝对值大于b2的绝对值
{
if (b1.value[0] == '+')
b3.value[0] = '+';
else
b3.value[0] = '-';
}
carry = 0;
for (int i = b1.value.Length - 1; i > 1; i--) //绝对值大的数减绝对值小的数
{
char[] a;
int n1 = int.Parse(b11.value[i].ToString());
int n2 = int.Parse(b22.value[i].ToString());
if (n1 + carry >= n2) //够减，无借位
{
a = (n1 + carry - n2).ToString().ToCharArray();
carry = 0;
}
else //不够减，要借位
{
a = (n1 + carry + 10 - n2).ToString().ToCharArray();
carry = -1;
}
b3.value[i] = a[a.Length - 1];
}
}
}
b3.valuestr = b3.Value_to_Str();
return b3;
}
// / 重载
public static BigInteger operator /(BigInteger b1, BigInteger b2)
{
BigInteger b3 = new BigInteger();
BigInteger b11 = new BigInteger();
BigInteger b22 = new BigInteger();
for (int i = 0; i < b11.value.Length; i++)
{
b11.value[i] = b1.value[i];
b22.value[i] = b2.value[i];
}
if ((b11 == "0") && (b22 != "0")) //被除数为0且除数不为0
{
b3.value[0] = '+';
for (int i = 1; i < b3.value.Length; i++)
b3.value[i] = '0';
}
else if (b22 == "0") //除数不能为0
{
Console.WriteLine("0 不能作为除数！");
return null;
}
else
{
b11.value[0] = '+'; //b11、b22取绝对值
b22.value[0] = '+';
b11.valuestr = b11.Value_to_Str();
b22.valuestr = b22.Value_to_Str();
int tem = 0;
while (b22.valuestr.Length < b11.valuestr.Length)//除数补成和被除数长度一样
{
for (int i1 = 1; i1 < b11.value.Length - 1; i1++)
b22.value[i1] = b22.value[i1 + 1];
b22.value[b11.value.Length - 1] = '0';
b22.valuestr = b22.Value_to_Str();
tem++; //记录补位个数
}
for (int a = tem; a >= 0; a--)
{
int b = 0;
while ((b11 - b22) > "0" || (b11 - b22) == "0")
{
b11 = b11 - b22;
b11.valuestr = b11.Value_to_Str();
b++; //记录能相减的次数并存到b3相应的位置
}
char[] ch = b.ToString().ToCharArray();
b3.value[b3.value.Length - 1 - a] = ch[ch.Length - 1];
for (int i1 = b11.value.Length - 1; i1 > 2; i1--) //每次撤销一个补位
b22.value[i1] = b22.value[i1 - 1];
b22.value[1] = '0';
}
if (((b1.value[0] == '+') && (b2.value[0] == '+')) || ((b1.value[0] == '-') && (b2.value[0] == '-'))) //同号为正
b3.value[0] = '+';
else //异号为负
b3.value[0] = '-';
b3.valuestr = b3.Value_to_Str();
}
return b3;
}
// - 重载
public static BigInteger operator -(BigInteger b1, BigInteger b2)
{
BigInteger b3 = new BigInteger();
BigInteger b11 = new BigInteger();
BigInteger b22 = new BigInteger();
for (int i = 0; i < b11.value.Length; i++)
{
b11.value[i] = b1.value[i];
b22.value[i] = b2.value[i];
}
if (b11 == b22) //被减数和减数相等
{
b3.value[0] = '+';
for (int i = 1; i < b3.value.Length; i++)
b3.value[i] = '0';
}
else
{
if (b22.value[0] == '+')
b22.value[0] = '-';
else b22.value[0] = '+';
b3 = b11 + b22;
}
return b3;
}