using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^((-?\d+(?:\.\d+)?)(?:[*+/^eE-]| (?:to the power of|plus|add|minus|subtract|divided?|times|multipl(?:y|ied))(?: by)?)(?: )?)(?1)*(?2)$";
string input = @"2*2
2+2
2/2
2-2
2^2-2
2^2
2e10^4
2^2^2^2+4
2+2+2+2
2 times 2
2 multiplied by 2
2 multiply 2
2 divide 2
2 divided by 2
2 add 2
2 plus 2
2 minus 2
2 subtract 2
2 to the power of 2 divided by 10
2 multiplied by 10 times 3
2.09187 times 9
-3 times 9
2+-6
2 multiplied by";
RegexOptions options = RegexOptions.Multiline;
foreach (Match m in Regex.Matches(input, pattern, options))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx