Program.cs - master - fxk/calcapi

Program.cs
108 строк2 KB
foxuk
Добавил "расчет" процента
10 мар 2025, 07:32
10 мар 2025, 07:32e072a61
using System.Globalization;
using System.Text.RegularExpressions;

var builder = WebApplication.CreateBuilder(args);
builder.WebHost.UseUrls(Environment.GetEnvironmentVariable("APP_URL") ?? "https://localhost:5000");

var app = builder.Build();

app.UseHttpsRedirection();

app.MapGet("/calc", (HttpContext context, string exp) =>
    {
        var tokens = Array.FindAll(MyRegex().Split(exp), s => !string.IsNullOrEmpty(s));
        Console.WriteLine(context.Connection.RemoteIpAddress + $" - {exp}");
        
        try
        {
            var result = EvalExpression(tokens);
            return result.ToString(CultureInfo.CurrentCulture);
        }
        catch (Exception e)
        {
            Console.WriteLine(e);
            return "error";
        }
        
    });

app.Run();

double EvalExpression(string[] tokens)
{
    var values = new Stack<double>();
    var operators = new Stack<string>();

    foreach (var token in tokens)
    {
        if (double.TryParse(token, out double value))
        {
            values.Push(value);
        }
        else
        {
            while (operators.Count > 0 && HasPrecedence(token, operators.Peek()))
            {
                ApplyOperator(values, operators.Pop());
            }
            operators.Push(token);
        }
    }

    while (operators.Count > 0)
    {
        ApplyOperator(values, operators.Pop());
    }

    return values.Pop();
}

static bool HasPrecedence(string op1, string op2)
{
    var precedence = new Dictionary<string, int>
    {
        {"+", 1},
        {"-", 1},
        {"*", 2},
        {"/", 2},
        {"^", 3},
        {"%", 3}
    };

    return precedence[op1] <= precedence[op2];
}

static void ApplyOperator(Stack<double> values, string op)
{
    var right = values.Pop();
    var left = values.Pop();

    switch (op)
    {
        case "+":
            values.Push(left + right);
            break;
        case "-":
            values.Push(left - right);
            break;
        case "*":
            values.Push(left * right);
            break;
        case "/":
            values.Push(left / right);
            break;
        case "^":
            values.Push(Math.Pow(left, right));
            break;
        case "%":
            // values.Push(left * (right / 100));
            values.Push(left / 100);
            break;
    }
}

partial class Program
{
    [GeneratedRegex(@"(\d+\.?\d*)|([-+*/^%])")]
    private static partial Regex MyRegex();
}