//Resolves only the provided operators
private static List <MathElement> ResolveOperators(List <MathElement> problem, string[] operators)
{
for (var i = 0; i < problem.Count; i++)
{
var element = problem[i];
if (element.IsOperator && operators.Contains(element.Operator))
{
var result = OperateOperators(problem[i - 1], element, problem[i + 1]);
problem[i - 1] = new MathElement(result);
problem.RemoveRange(i, 2);
i--;
}
}
return(problem);
}
public static double DoMath(string input)
{
var problem = StringToProblem(input);
//Resolve the Parenthesis deepest first one at a time.
while (DeepestNestedProblem(problem).Success)
{
var(_, start, length) = DeepestNestedProblem(problem);
var result = ResolveProblem(problem.GetRange(start + 1, length - 1));
problem[start] = new MathElement(result); // replace the ( of the nested statement with the result of the problem
problem.RemoveRange(start + 1, length); //remove everything past the opening ( from the list
}
//Resolve the final unparenthesized problem
return(ResolveProblem(problem));
}
private static List <MathElement> StringToProblem(string input)
{
var problem = new List <MathElement>();
var number = "";
for (var i = 0; i < input.Length; i++)
{
//is it a digit or a ., remember it
var symbol = input[i];
if (IsDigit(symbol) || symbol == '.')
{
number += symbol;
}
//is not a digit or a . then add any remember digits and. to the problem as a number and clear the remembered ones
if (!(IsDigit(symbol) || symbol == '.') && !string.IsNullOrWhiteSpace(number))
{
var element = new MathElement(number);
problem.Add(element);
number = "";
}
//its not a digit or a . so it must be a symbol to add to the problem
if (!(IsDigit(symbol) || symbol == '.') && !string.IsNullOrWhiteSpace(symbol.ToString()))
{
var element = new MathElement(symbol);
problem.Add(element);
}
}
//Trailing number
if (!string.IsNullOrWhiteSpace(number))
{
var element = new MathElement(number);
problem.Add(element);
}
return(problem);
}
private static double OperateOperators(MathElement valA, MathElement op, MathElement valB)
{
return(OperateOperators(valA.Value, op.Operator, valB.Value));
}
