private static LargeInteger MultiplyBy10(LargeInteger value)
{
char[] output = new char[value.ToString().Length + 1];
string str = ReverseStr(value.ToString());
for (int j = str.Length - 1; j >= 0; j--)
{
output[j + 1] = str[j];
}
output[0] = '0';
return new LargeInteger(ReverseStr(new string(output)));
}
private static LargeInteger positiveMultiplyPositive(LargeInteger int1, LargeInteger int2)
{
string str = ReverseStr(int2.ToString());
LargeInteger multiplicationCarry = null;
LargeInteger result = new LargeInteger("0");
for (int j = 0; j < str.Length; j++)
{
int digit = Convert.ToInt32(str[j].ToString());
multiplicationCarry = MultiplyDigit(int1, digit);
for (int k = 0; k < j; k++)
{
multiplicationCarry = MultiplyBy10(multiplicationCarry);
}
result = result + multiplicationCarry;
}
return result;
}
private static LargeInteger bigMinusSmall(LargeInteger int1, LargeInteger int2)
{
char[] output = new char[Math.Max(int1.ToString().Length, int2.ToString().Length) + 1];
string str1 = ReverseStr(int1.ToString());
string str2 = ReverseStr(int2.ToString());
int length1 = str1.Length;
int length2 = str2.Length;
int maxLength = length1 > length2 ? length1 : length2;
int carry = 0;
for (int j = 0; j < maxLength; j++)
{
int digit1 = 0;
if (j > 0 && j < length1 - 1)
digit1 = Convert.ToInt32(str1[j].ToString()) + 10;
else if (j > length1 - 1)
digit1 = 0;
else if (j == 0 || j == length1 - 1)
digit1 = Convert.ToInt32(str1[j].ToString());
int digit2 = (j > length2 - 1) ? 0 : Convert.ToInt32(str2[j].ToString());
int digitsum = digit1 - digit2 + carry;
if (digitsum >= 10)
{
digitsum -= 10;
carry = 0;
}
else if (digitsum < 10 && digitsum >= 0)
{
carry = j > 0 ? -1 : 0;
}
else if (digitsum < 0)
{
digitsum = -digitsum;
carry = -1;
}
output[j] = Convert.ToChar(Convert.ToString(digitsum));
}
return new LargeInteger(ReverseStr(new string(output)));
}
private static LargeInteger MultiplyDigit(LargeInteger number, int digit)
{
char[] output = new char[number.ToString().Length + 1];
int carry = 0;
string str = ReverseStr(number.ToString());
int j = 0;
for (j = 0; j < str.Length; j++)
{
int digit1 = Convert.ToInt32(str[j].ToString());
int digitProduct = digit1 * digit;
digitProduct += carry;
if (digitProduct >= 10)
{
carry = digitProduct / 10;
digitProduct -= carry * 10;
}
else
carry = 0;
output[j] = Convert.ToChar(Convert.ToString(digitProduct));
}
if (carry != 0)
output[j++] = Convert.ToChar(Convert.ToString(carry));
return new LargeInteger(ReverseStr(new string(output)));
}
private static LargeInteger positivePlusPositive(LargeInteger int1, LargeInteger int2)
{
char[] output = new char[Math.Max(int1.ToString().Length, int2.ToString().Length) + 1];
string str1 = ReverseStr(int1.ToString());
string str2 = ReverseStr(int2.ToString());
int length1 = str1.Length;
int length2 = str2.Length;
int maxLength = length1 > length2 ? length1 : length2;
int carry = 0;
int j = 0;
for (j = 0; j < maxLength; j++)
{
int digit1 = (j > length1 - 1) ? 0 : Convert.ToInt32(str1[j].ToString());
int digit2 = (j > length2 - 1) ? 0 : Convert.ToInt32(str2[j].ToString());
int digitsum = digit1 + digit2 + carry;
if (digitsum >= 10)
{
digitsum -= 10;
carry = 1;
}
else
carry = 0;
output[j] = Convert.ToChar(Convert.ToString(digitsum));
}
if (carry == 1)
{
output[j++] = '1';
}
string str = ReverseStr(new string(output));
return new LargeInteger(str);
}
public static string RunWithParameter(string option, string command)
{
Console.WriteLine("Now test input: " + command);
string operation = string.Empty;
if (option == "1")
{
operation = "addition";
}
else if (option == "2")
{
operation = "subtraction";
}
else if (option == "3")
{
operation = "multiplication";
}
Console.WriteLine("Computation: " + operation);
List <string> numbers = Utilities.ProcessCommand(command.Trim());
if (numbers.Count == 0)
{
Console.WriteLine("There is no invalid integers in the input command.");
return(string.Empty);
}
else if (numbers.Count == 1)
{
Console.WriteLine("There is only one valid integer in the input command: " + numbers[0] +
", no calculation is needed.");
return(numbers[0]);
}
else
{
string formula = string.Empty;
LargeInteger result = new LargeInteger(numbers[0]);
switch (option)
{
case "1":
formula = string.Join(" + ", numbers.ToArray());
for (int i = 1; i < numbers.Count(); i++)
{
result += new LargeInteger(numbers[i]);
}
break;
case "2":
formula = string.Join(" - ", numbers.ToArray());
for (int i = 1; i < numbers.Count(); i++)
{
result -= new LargeInteger(numbers[i]);
}
break;
case "3":
formula = string.Join(" * ", numbers.ToArray());
for (int i = 1; i < numbers.Count(); i++)
{
result *= new LargeInteger(numbers[i]);
}
break;
}
Console.WriteLine("Formula: " + formula);
Console.WriteLine("Result = " + result);
Console.WriteLine("********* END OF THIS TEST CASE");
Console.WriteLine();
return(result.ToString());
}
}
// Subtraction
public static LargeInteger operator -(LargeInteger int1, LargeInteger int2)
{
// Step 1. positive/negative check for int1 and int2
string str1 = int1.ToString();
string str2 = int2.ToString();
LargeInteger trueInt1 = new LargeInteger(str1);
LargeInteger trueInt2 = new LargeInteger(str2);
// If the number is negative, remove "-" sign and handle the +/- sign manually
if (str1[0] == '-' && str2[0] == '-')
{
trueInt1 = new LargeInteger(str2.Remove(0, 1).TrimStart('0'));
trueInt2 = new LargeInteger(str1.Remove(0, 1).TrimStart('0'));
if (string.IsNullOrEmpty(trueInt1.value))
trueInt1.value = "0";
if (string.IsNullOrEmpty(trueInt2.value))
trueInt2.value = "0";
}
else if (str1[0] == '-' && str2[0] != '-')
{
trueInt1 = new LargeInteger(str1.Remove(0, 1).TrimStart('0'));
LargeInteger intermidateResult = trueInt1 + trueInt2;
return intermidateResult.value == "0" ? new LargeInteger("0")
: new LargeInteger("-" + intermidateResult.ToString());
}
else if (str1[0] != '-' && str2[0] == '-')
{
trueInt2 = new LargeInteger(str2.Remove(0, 1).TrimStart('0'));
return trueInt1 + trueInt2;
}
// If it can reach here (both number are positive), proceed to step. 2
// Step 2. compare which is larger: int1 or int2, since method "bigMinusSmall" requries int1 to be larger,
// switch order of subtraction and manually add negative sign if necessary
bool int1Larger = true;
int length1 = trueInt1.ToString().Length;
int length2 = trueInt2.ToString().Length;
// newInt1, newInt2 are used to compare which is larger
LargeInteger newInt1 = trueInt1;
LargeInteger newInt2 = trueInt2;
if (length1 < length2)
{
string zeros = string.Empty;
for (int i = 0; i < length2 - length1; i++)
zeros += "0";
newInt1 = new LargeInteger(zeros + trueInt1.ToString());
}
else if (length1 > length2)
{
string zeros = string.Empty;
for (int i = 0; i < length1 - length2; i++)
zeros += "0";
newInt2 = new LargeInteger(zeros + trueInt2.ToString());
}
string strNewInt1 = newInt1.value;
string strNewInt2 = newInt2.value;
for (int i = 0; i < strNewInt1.Length; i++)
{
int number1 = Convert.ToInt32(strNewInt1[i].ToString());
int number2 = Convert.ToInt32(strNewInt2[i].ToString());
if (number2 < number1)
{
break;
}
else if (number2 > number1)
{
int1Larger = false;
break;
}
}
return int1Larger ? bigMinusSmall(trueInt1, trueInt2) : new LargeInteger("-" + bigMinusSmall(trueInt2, trueInt1));
}
