❔ Lexer and parser, cannot get expressions to formulate as they should, have a look at the output...

        static void Lexer(string input)
        {
            char[] delimiters = "!@#$%^&()=_{}|\\][:\"';?><,.` ".ToCharArray();
            string[] words;
            Dictionary<string, int> tokens = new Dictionary<string, int>();

            words = input.Split(delimiters, StringSplitOptions.RemoveEmptyEntries);
            
            Console.WriteLine(">>> Tokens:");
            foreach (string word in words)
            {
                if (tokens.ContainsKey(word))
                {
                    tokens[word] += 1;
                }
                else
                {
                    tokens.Add(word, 1);
                }
            }
            foreach (KeyValuePair<string, int> token in tokens)
            {
                Console.WriteLine($">>> {token.Key} : {token.Value}");
            }
            Parser(tokens);
        }

        static void Parser(Dictionary<string, int> tokens)
        {
            string expression = String.Empty;
            string[] operators =
            {
                "+", "-", "*", "/"
            };
            string[] nums =
            {
                "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"
            };

            foreach (KeyValuePair<string, int> token in tokens)
            {
                if (operators.Contains(token.Key))
                {
                    Console.WriteLine($">>> Operator:\t{token.Key}");
                }
                else if (nums.Contains(token.Key))
                {
                    Console.WriteLine($">>> Number:\t{token.Key}");
                }
                else
                {
                    Console.WriteLine($">>> Identifier:\t{token.Key}");
                }
                expression += token.Key;
            }
            Console.WriteLine($">>> Expression: {expression}");
        }
    }
}

        static void Lexer(string input)
        {
            char[] delimiters = "!@#$%^&()=_{}|\\][:\"';?><,.` ".ToCharArray();
            string[] words;
            Dictionary<string, int> tokens = new Dictionary<string, int>();

            words = input.Split(delimiters, StringSplitOptions.RemoveEmptyEntries);
            
            Console.WriteLine(">>> Tokens:");
            foreach (string word in words)
            {
                if (tokens.ContainsKey(word))
                {
                    tokens[word] += 1;
                }
                else
                {
                    tokens.Add(word, 1);
                }
            }
            foreach (KeyValuePair<string, int> token in tokens)
            {
                Console.WriteLine($">>> {token.Key} : {token.Value}");
            }
            Parser(tokens);
        }

        static void Parser(Dictionary<string, int> tokens)
        {
            string expression = String.Empty;
            string[] operators =
            {
                "+", "-", "*", "/"
            };
            string[] nums =
            {
                "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"
            };

            foreach (KeyValuePair<string, int> token in tokens)
            {
                if (operators.Contains(token.Key))
                {
                    Console.WriteLine($">>> Operator:\t{token.Key}");
                }
                else if (nums.Contains(token.Key))
                {
                    Console.WriteLine($">>> Number:\t{token.Key}");
                }
                else
                {
                    Console.WriteLine($">>> Identifier:\t{token.Key}");
                }
                expression += token.Key;
            }
            Console.WriteLine($">>> Expression: {expression}");
        }
    }
}