If you want to run the benchmarks you need to run the application without attaching it to the debugger and in Release mode:
dotnet run -c Release
The mapping of Morse characters to regular characters is as follows:
[".-"] = 'a',
["-..."] = 'b',
["-.-."] = 'c',
["-.."] = 'd',
["."] = 'e',
["..-."] = 'f',
["--."] = 'g',
["...."] = 'h',
[".."] = 'i',
[".---"] = 'j',
["-.-"] = 'k',
[".-.."] = 'l',
["--"] = 'm',
["-."] = 'n',
["---"] = 'o',
[".--."] = 'p',
["--.-"] = 'q',
[".-."] = 'r',
["..."] = 's',
["-"] = 't',
["..-"] = 'u',
["...-"] = 'v',
[".--"] = 'w',
["-..-"] = 'x',
["-.--"] = 'y',
["--.."] = 'z',
[".----"] = '1',
["..---"] = '2',
["...--"] = '3',
["....-"] = '4',
["....."] = '5',
["-...."] = '6',
["--..."] = '7',
["---.."] = '8',
["----."] = '9',
["-----"] = '0',