using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
					
public class Program
{
	public static void Main()
	{
		DecryptString("BQO5l5Kj9MdErXx6Q6AGOw==", "c4scadek3y654321");
	}
	
	public static string EncryptString(string Plaintext, string Key)
        {
            byte[] bytes = Encoding.UTF8.GetBytes(Plaintext);
            Aes aes = Aes.Create();
            aes.BlockSize = 128;
            aes.KeySize = 128;
            aes.IV = Encoding.UTF8.GetBytes("1tdyjCbY1Ix49842");
            aes.Key = Encoding.UTF8.GetBytes(Key);
            aes.Mode = CipherMode.CBC;
            string result;
            using (MemoryStream memoryStream = new MemoryStream())
            {
                using (CryptoStream cryptoStream = new CryptoStream(memoryStream, aes.CreateEncryptor(), CryptoStreamMode.Write))
                {
                    cryptoStream.Write(bytes, 0, bytes.Length);
                    cryptoStream.FlushFinalBlock();
                }
                result = Convert.ToBase64String(memoryStream.ToArray());
            }
            return result;
        }
	
	public static string DecryptString(string EncryptedString, string Key)
        {
            byte[] array = Convert.FromBase64String(EncryptedString);
            Aes aes = Aes.Create();
            aes.KeySize = 128;
            aes.BlockSize = 128;
            aes.IV = Encoding.UTF8.GetBytes("1tdyjCbY1Ix49842");
            aes.Mode = CipherMode.CBC;
            aes.Key = Encoding.UTF8.GetBytes(Key);
            string @string;
            using (MemoryStream memoryStream = new MemoryStream(array))
            {
                using (CryptoStream cryptoStream = new CryptoStream(memoryStream, aes.CreateDecryptor(), CryptoStreamMode.Read))
                {
                    byte[] array2 = new byte[checked(array.Length - 1 + 1)];
                    cryptoStream.Read(array2, 0, array2.Length);
                    @string = Encoding.UTF8.GetString(array2);
                }
            }
		Console.WriteLine(@string);
            return @string;
        }
	
	
} 

C Sharp Online Compiler

Write, Run & Share C# code online using OneCompiler's C# online compiler for free. It's one of the robust, feature-rich online compilers for C# language, running on the latest version 8.0. Getting started with the OneCompiler's C# compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C# and start coding.

Read inputs from stdin

OneCompiler's C# online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.

using System;
 
namespace Sample
{
  class Test
    {
      public static void Main(string[] args)
       {
         string name;
         name = Console.ReadLine();
         Console.WriteLine("Hello {0} ", name);
	}
     }
}

About C Sharp

C# is a general purpose object-oriented programming language by Microsoft. Though initially it was developed as part of .net but later it was approved by ECMA and ISO standards.

You can use C# to create variety of applications, like web, windows, mobile, console applications and much more using Visual studio.

Syntax help

Data types

Data TypeDescriptionRangesize
intTo store integers-2,147,483,648 to 2,147,483,6474 bytes
doubleto store large floating point numbers with decimalscan store 15 decimal digits8 bytes
floatto store floating point numbers with decimalscan store upto 7 decimal digits4 bytes
charto store single characters-2 bytes
stringto stores text-2 bytes per character
boolto stores either true or false-1 bit

Variables

Syntax

datatype variable-name = value;

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition or set of few conditions IF-ELSE is used.

if(conditional-expression) {
   // code
} 
else {
   // code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression) {    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
...    
    
default:     
 // code to be executed when all the above cases are not matched;    
} 

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement) {
  // code  
} 

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while(condition) {
 // code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {
  // code 
} while (condition);

Arrays

Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.

Syntax

data-type[] array-name;

Methods

Method is a set of statements which gets executed only when they are called. Call the method name in the main function to execute the method.

Syntax

static void method-name() 
{
  // code to be executed
}