private static BigInt Reduce(BigInt a, BigInt b)//вычитает из большего меньшее два бигинта
{
if (a == b)
{
return(Zero);
}
if (b.sign == '-')
{
return(Addition(a, b));
}
a.DeleteNuls(); b.DeleteNuls();
b.EqualizeTheDigits(a.number.Count);
var res = new BigInt();
var num1 = new List <int>(a.number); var num2 = new List <int>(b.number);
for (var i = a.number.Count - 1; i >= 0; i--)
{
var r = num1[i] - num2[i];
if (r < 0)
{
num1[i - 1]--;
r = 10 + r;
}
res.SetDigit(i, r);
}
res.DeleteNuls();
return(res);
}
public static BigInt operator *(BigInt V1, BigInt V2) // v1 * v2
{
V1.DeleteNuls(); V2.DeleteNuls();
var result = new BigInt();
result.EqualizeTheDigits(V1.number.Count + V2.number.Count);
V1.number.Reverse(); V2.number.Reverse();
for (var i = 0; i < V1.number.Count; ++i)
{
for (int j = 0, carry = 0; j < V2.number.Count || carry > 0; ++j)
{
var cur = result.number[i + j] + V1.number[i] * (j < V2.number.Count ? V2.number[j] : 0) + carry;
result.number[i + j] = cur % 10;
carry = cur / 10;
}
}
while (result.number.Count > 1 && result.number.Last() == 0)
{
result.number.RemoveAt(result.number.Count - 1);
}
result.sign = V1.sign == V2.sign ? '+' : '-';
V1.number.Reverse(); V2.number.Reverse();
result.number.Reverse();
result.DeleteNuls();
return(result);
}
private static BigInt Addition(BigInt a, BigInt b)//суммирует два бигинта
{
var res = new BigInt();
var maxLen = Math.Max(a.number.Count, b.number.Count) - 1;
var enlarge = 0;
var num1 = a.number; var num2 = b.number; var resNum = res.number;
if (num1.Count < num2.Count)
{
a.EqualizeTheDigits(b.number.Count);
res.EqualizeTheDigits(b.number.Count);
}
else
{
b.EqualizeTheDigits(a.number.Count);
res.EqualizeTheDigits(a.number.Count);
}
for (var i = maxLen; i >= 0; i--)
{
var s = num1[i] + num2[i] + enlarge;
if (s >= 10)
{
enlarge = 1;
resNum[i] = s - 10;
}
else
{
enlarge = 0;
resNum[i] = s;
}
}
if (enlarge == 1)
{
resNum.Insert(0, 1);
}
res.DeleteNuls();
return(res);
}
