C# Online Compiler | .NET Fiddle

<no name> by Anonymous

using System;
					
public class Program
{
	public static void Main()
	{
		 Console. WriteLine("Введите день");
		 int D = Convert.ToInt16(Console.ReadLine());
		
		 Console.WriteLine("Введите месяц");
         int M = Convert.ToInt16(Console.ReadLine());
		
		
			switch (M)
            {
                case 1:
					if (D == 31)
					{
						D -= 1;
						M -= 1;
						break;
					}
					else if (D == 1)
					{
						D = 31;
						M = 12;
						break;
					}
					else { D -= 1; M -= 1; break; }
                
				case 2:
                    if (D == 28)
                    {
                        D -= 1;
                        M -= 1;
                        break;
                    }
					else if (D == 1)
					{
						D = 31;
						M = 1;
						break;
					}
                    else { D -= 1; M -= 1; break; }
                 
				case 3:
					if (D == 31)
					{
						D -= 1;
						M -= 1;
						break;
					}
					else if (D == 1)
					{
						D = 28;
						M = 2;
						break;
					}
					else { D -= 1; M -= 1; break; }
				  
				case 4:
					if (D == 31)
					{
						D -= 1;
						M -= 1;
						break;
					}
					else if (D == 1)
					{
						D = 31;
						M = 3;
						break;
					}
					else { D -= 1; M -= 1; break; }	
			
				case 5:
					if (D == 31)
					{
						D -= 1;
						M -= 1;
						break;
					}
					else if (D == 1)
					{
						D = 30;
						M = 4;
						break;
					}
					else { D -= 1; M -= 1; break; }
					
				case 6:
                    if (D == 30)
                    {
                        D -= 1;
                        M -= 1;
                        break;
                    }
					else if (D == 1)
					{
						D = 30;
						M = 5;
						break;
					}
                    else { D -= 1; M -= 1; break; }
				
					
				case 7:
					if (D == 31)
					{
						D -= 1;
						M -= 1;
						break;
					}
					else if (D == 1)
					{
						D = 30;
						M = 6;
						break;
					}
					else { D -= 1; M -= 1; break; }
				
				case 8:
					if (D == 31)
					{
						D -= 1;
						M -= 1;
						break;
					}
					else if (D == 1)
					{
						D = 31;
						M = 7;
						break;
					}
					else { D -= 1; M -= 1; break; }
					
				case 9:
					if (D == 31)
					{
						D -= 1;
						M -= 1;
						break;
					}
					else if (D == 1)
					{
						D = 31;
						M = 8;
						break;
					}
					else { D -= 1; M -= 1; break; }
					
				case 10:
					if (D == 31)
					{
						D -= 1;
						M -= 1;
						break;
					}
					else if (D == 1)
					{
						D = 31;
						M = 9;
						break;
					}
					else { D -= 1; M -= 1; break; }
					
					case 11:
					if (D == 31)
					{
						D -= 1;
						M -= 1;
						break;
					}
					else if (D == 1)
					{
						D = 30;
						M = 10;
						break;
					}
					else { D -= 1; M -= 1; break; }
					
					
				case 12:
					if (D == 31)
					{
						D -= 1;
						M -= 1;
						break;
					}
					else if (D == 1)
					{
						D = 31;
						M = 11;
						break;
					}
					else { D -= 1; M -= 1; break; }
            }
				 Console.WriteLine("Предшествующий день: {0}\nПредшествуюший Месяц: {1}", D, M);
	}
}

 
using System;
                    
public class Program
{
    public static void Main()
    {
         Console. WriteLine("Введите день");
         int D = Convert.ToInt16(Console.ReadLine());
        
         Console.WriteLine("Введите месяц");
         int M = Convert.ToInt16(Console.ReadLine());
        
        
            switch (M)
            {
                case 1:
                    if (D == 31)
                    {
                        D -= 1;
                        M -= 1;
                        break;
                    }
                    else if (D == 1)
                    {
                        D = 31;
                        M = 12;
                        break;
                    }
                    else { D -= 1; M -= 1; break; }
                
                case 2:
                    if (D == 28)
                    {
                        D -= 1;
                        M -= 1;
                        break;
                    }
                    else if (D == 1)
                    {
                        D = 31;
                        M = 1;
                        break;
                    }
                    else { D -= 1; M -= 1; break; }
                 
                case 3:
                    if (D == 31)
                    {
                        D -= 1;
                        M -= 1;
                        break;
                    }
                    else if (D == 1)
                    {
                        D = 28;
                        M = 2;
                        break;
                    }
                    else { D -= 1; M -= 1; break; }
                  
                case 4:
                    if (D == 31)
                    {
                        D -= 1;
                        M -= 1;
                        break;
                    }
                    else if (D == 1)
                    {
                        D = 31;
                        M = 3;
                        break;
                    }
                    else { D -= 1; M -= 1; break; } 
            
                case 5:
                    if (D == 31)
                    {
                        D -= 1;
                        M -= 1;
                        break;
                    }
                    else if (D == 1)
                    {
                        D = 30;
                        M = 4;
                        break;
                    }
                    else { D -= 1; M -= 1; break; }
                    
                case 6:
                    if (D == 30)
                    {
                        D -= 1;
                        M -= 1;
                        break;
                    }
                    else if (D == 1)
                    {
                        D = 30;
                        M = 5;
                        break;
                    }
                    else { D -= 1; M -= 1; break; }
                
                    
                case 7:
                    if (D == 31)
                    {
                        D -= 1;
                        M -= 1;
                        break;
                    }
                    else if (D == 1)
                    {
                        D = 30;
                        M = 6;
                        break;
                    }
                    else { D -= 1; M -= 1; break; }
                
                case 8:
                    if (D == 31)
                    {
                        D -= 1;
                        M -= 1;
                        break;
                    }
                    else if (D == 1)
                    {
                        D = 31;
                        M = 7;
                        break;
                    }
                    else { D -= 1; M -= 1; break; }
                    
                case 9:
                    if (D == 31)
                    {
                        D -= 1;
                        M -= 1;
                        break;
                    }
                    else if (D == 1)
                    {
                        D = 31;
                        M = 8;
                        break;
                    }
                    else { D -= 1; M -= 1; break; }
                    
                case 10:
                    if (D == 31)
                    {
                        D -= 1;
                        M -= 1;
                        break;
                    }
                    else if (D == 1)
                    {
                        D = 31;
                        M = 9;
                        break;
                    }
                    else { D -= 1; M -= 1; break; }
                    
                    case 11:
                    if (D == 31)
                    {
                        D -= 1;
                        M -= 1;
                        break;
                    }
                    else if (D == 1)
                    {
                        D = 30;
                        M = 10;
                        break;
                    }
                    else { D -= 1; M -= 1; break; }
                    
                    
                case 12:
                    if (D == 31)
                    {
                        D -= 1;
                        M -= 1;
                        break;
                    }
                    else if (D == 1)
                    {
                        D = 31;
                        M = 11;
                        break;
                    }
                    else { D -= 1; M -= 1; break; }
            }
                 Console.WriteLine("Предшествующий день: {0}\nПредшествуюший Месяц: {1}", D, M);
    }
}

Compilation error (line 0, col 0): Metadata file 'C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.7.2\Facades\mscorlib.dll' could not be found
Compilation error (line 0, col 0): Metadata file 'c:\LocalResources\NuGet\Packages\RestClient\3.446.20952.0\lib\net472\RestClient.dll' could not be found
Compilation error (line 0, col 0): Metadata file 'c:\LocalResources\NuGet\Packages\Microsoft.Extensions.Logging.Abstractions\3.1.4.0\lib\netstandard2.0\Microsoft.Extensions.Logging.Abstractions.dll' could not be found
Compilation error (line 0, col 0): Metadata file 'c:\LocalResources\NuGet\Packages\Microsoft.Extensions.Configuration.Json\3.1.4.0\lib\netstandard2.0\Microsoft.Extensions.Configuration.Json.dll' could not be found

Last Run:	8:05:49 am
Compile:	0s
Execute:	0.206s
Memory:	0b
CPU:	0s

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