public static Double CalculateRPN(string rpnString, double[] values)
{
Stack <Double> numbersStack = new Stack <Double>();
Double value1, value2;
int pos = 0;
string variable = "";
for (int i = 0; i < rpnString.Length; i++)
{
if (SignChecker.isVariable(rpnString[i]))
{
variable += rpnString[i];
}
else if (rpnString[i] == ' ')
{
if (variable != "")
{
numbersStack.Push(int.Parse(variable));
}
variable = "";
}
else
{
if (variable != "")
{
numbersStack.Push(int.Parse(variable));
variable = "";
}
value2 = numbersStack.Pop();
value1 = numbersStack.Pop();
numbersStack.Push(SignChecker.useOperator(rpnString[i], value1, value2));
}
}
return(numbersStack.Pop());
}
//Checks function
public static bool checkInputString(string formula)
{
int counter1 = 0,
counter2 = 2;
//Returns false if first symbol in function is operation (besides minus)
if (SignChecker.isOperation(formula[0]) && formula[0] != '-')
{
return(false);
}
//Returs false if last symbol in string is operation
if (SignChecker.isOperation(formula[formula.Length - 1]))
{
return(false);
}
//Counts ammount of opening and closing brackets
counter1 = formula.ToCharArray().Where(x => x == '(').Count();
counter2 = formula.ToCharArray().Where(x => x == ')').Count();
//If ammount of brackets doesn't equal, then returns false
if (counter1 != counter2)
{
return(false);
}
//Checks if there is no two operations side by side
for (int i = 1; i < formula.Length; i++)
{
if (SignChecker.isOperation(formula[i]) && SignChecker.isOperation(formula[i - 1]))
{
return(false);
}
}
return(true);
}
public static bool checkInputString(string formula)
{
int counter1 = 0,
counter2 = 2;
if (SignChecker.isOperation(formula[0]) && formula[0] != '-')
{
return(false);
}
if (SignChecker.isOperation(formula[formula.Length - 1]))
{
return(false);
}
counter1 = formula.ToCharArray().Where(x => x == '(').Count();
counter2 = formula.ToCharArray().Where(x => x == ')').Count();
if (counter1 != counter2)
{
return(false);
}
for (int i = 1; i < formula.Length; i++)
{
if (SignChecker.isOperation(formula[i]) && SignChecker.isOperation(formula[i - 1]))
{
return(false);
}
}
return(true);
}
//Calculating function
public static Double CalculateRPN(string rpnString, List <string> variables, double[] values)
{
Stack <Double> numbersStack = new Stack <Double>(); //stack for numbers
Double value1, value2; //first and second values
string variable = ""; //Current variable
//Replaces all variables from rpn string to variables values
for (int i = 0; i < variables.Count; i++)
{
rpnString = rpnString.Replace(variables[i], values[i].ToString());
}
for (int i = 0; i < rpnString.Length; i++)
{
//If current symbol is variable
if (SignChecker.isVariable(rpnString[i]))
{
//Add to variable
variable += rpnString[i];
}
else if (rpnString[i] == ' ')
{
//If current symbol is space and we have something in variable
if (variable != "")
{
//Add variable to stack
numbersStack.Push(double.Parse(variable));
}
variable = "";
}
else if (rpnString[i] == '-' && i != rpnString.Length - 1 && SignChecker.isVariable(rpnString[i + 1]))
{
variable += rpnString[i];
}
else
{
//If variable has something
if (variable != "")
{
//Add to stack
numbersStack.Push(double.Parse(variable));
variable = "";
}
//Take two values from stack
value2 = numbersStack.Pop();
value1 = numbersStack.Pop();
//Calculate them
numbersStack.Push(SignChecker.useOperator(rpnString[i], value1, value2));
}
}
if (variable != "")
{
numbersStack.Push(double.Parse(variable));
}
return(numbersStack.Pop());
}
public static IEnumerable <string> findAllX(string rpnString)
{
Stack <Double> numbersStack = new Stack <Double>();
List <string> stringList = new List <string>();
string variable = "";
for (int i = 0; i < rpnString.Length; i++)
{
if (SignChecker.isVariable(rpnString[i]))
{
variable += rpnString[i];
}
else
{
if (variable.Any(c => char.IsLetter(c)))
{
stringList.Add(variable);
}
variable = "";
}
}
return(stringList.Distinct());
}
//Finding all variables in rpnString
public static List <string> findAllX(string rpnString)
{
Stack <Double> numbersStack = new Stack <Double>(); //Stack for numbers
List <string> stringList = new List <string>(); //List of all variables
string variable = "";
for (int i = 0; i < rpnString.Length; i++)
{
//If current symbol is variable
if (SignChecker.isVariable(rpnString[i]))
{
//Add to current variable
variable += rpnString[i];
}
else
{
//If variable has symbols in itself
if (variable.Any(c => char.IsLetter(c)))
{
//Add variable to variable list
stringList.Add(variable);
}
variable = "";
}
}
if (variable != "")
{
//If variable has symbols in itself
if (variable.Any(c => char.IsLetter(c)))
{
//Add variable to variable list
stringList.Add(variable);
}
}
//Return list of variables
return(stringList.Distinct().ToList());
}
public static string toRPN(string infixString)
{
if (!CheckInput.checkInputString(infixString))
{
return("");
}
Stack <char> operationStack = new Stack <char>(); //Stack for all operations
char lastOperation;
string resultString = ""; //String with result
infixString = infixString.Replace(" ", "");
for (int i = 0; i < infixString.Length; i++)
{
//If it is number, than add to resultString
if (SignChecker.isVariable(infixString[i]))
{
resultString += infixString[i];
}
else if (SignChecker.isOperation(infixString[i]))
{
if (infixString[i] == '-' && (((i == 0) || (infixString[i - 1] == '(')) && (SignChecker.isVariable(infixString[i + 1]))))
{
resultString += 0;
}
if (operationStack.Count != 0)
{
lastOperation = operationStack.Peek();
if (SignChecker.getOperationPriority(lastOperation) < SignChecker.getOperationPriority(infixString[i]))
{
operationStack.Push(infixString[i]);
resultString += " ";
}
else
{
resultString += operationStack.Pop();
operationStack.Push(infixString[i]);
resultString += " ";
}
}
else
{
resultString += " ";
operationStack.Push(infixString[i]);
}
}
//If current symbol is (, then add it to stack
else if (infixString[i] == '(')
{
operationStack.Push(infixString[i]);
}
//If current symbol is ), then return all symbols from stack, until (
else if (infixString[i] == ')')
{
while (operationStack.Peek() != '(')
{
resultString += operationStack.Pop();
}
operationStack.Pop();
}
}
//In the end, return all the values from stack
while (operationStack.Count != 0)
{
resultString += operationStack.Pop() + " ";
}
return(resultString);
}
public static string toRPN(string infixString)
{
infixString = infixString.Replace(" ", ""); //Replacing all spaces
if (!CheckInput.checkInputString(infixString)) //If we have wrong input string
{
throw new ArgumentException(); //Than throw exception
}
Stack <char> operationStack = new Stack <char>(); //Stack for all operations
char lastOperation; //Keeping last operation
string resultString = ""; //String with result
for (int i = 0; i < infixString.Length; i++)
{
//If it is number, than add to resultString
if (SignChecker.isVariable(infixString[i]))
{
resultString += infixString[i];
}
//If it is operation
else if (SignChecker.isOperation(infixString[i]))
{
//If it is unary minus< then add 0 to result string
if (infixString[i] == '-' && (((i == 0) || (infixString[i - 1] == '(')) && (SignChecker.isVariable(infixString[i + 1]))))
{
resultString += 0;
}
//If we have operations in stack
if (operationStack.Count != 0)
{
//Taking last operation of stack
lastOperation = operationStack.Peek();
//If priority of operation from stack is higher, then pirority of current operation
if (SignChecker.getOperationPriority(lastOperation) < SignChecker.getOperationPriority(infixString[i]))
{
//Add current operation to stack
operationStack.Push(infixString[i]);
resultString += " ";
}
else
{
//Add operation from stack to result string
resultString += operationStack.Pop();
//Add current operation to stack
operationStack.Push(infixString[i]);
resultString += " ";
}
}
else
{
//Add current operation to stack
resultString += " ";
operationStack.Push(infixString[i]);
}
}
//If current symbol is (, then add it to stack
else if (infixString[i] == '(')
{
operationStack.Push(infixString[i]);
}
//If current symbol is ), then return all symbols from stack, until (
else if (infixString[i] == ')')
{
while (operationStack.Peek() != '(')
{
resultString += operationStack.Pop();
}
operationStack.Pop();
}
}
//In the end, return all the values from stack
while (operationStack.Count != 0)
{
resultString += operationStack.Pop() + " ";
}
return(resultString);
}
