## Problem

**String Compression**
Implement a method to perform basic string compression using the counts of repeated characters.
**For Example**: the string aabcccccaaa would become a2b1c5a3

 * If the compressed string would not become smaller than the original string,
 * your method should return the original string.
 * you can assume the string has only uppercase and lowercase letter (a-z)

## Program

```js
/**
 * String Compression
 * Implement a method to perform basic string compression using the counts of repeated characters.
 * For Example: the string aabcccccaaa would become a2b1c5a3
 * If the compressed string would not become smaller than the original string,
 * your method should return the original string.
 * you can assume the string has only uppercase and lowercase letter (a-z)
 */

function stringCompression(str) {
    const stringLength = str.length;
    let compressedString = '';
    let charCount = 1;

    for (let i = 0; i < stringLength; i++) {
        
        if (str[i] === str[i+1]) {
            charCount ++;
        }
        else {
            compressedString += str[i];
            compressedString += charCount;
            charCount = 1;
        }
    }

    if (compressedString.length > stringLength) {
        return str;
    }
    else {
        return compressedString;
    }
}

console.log(stringCompression('aabcccccaaa'));
console.log(stringCompression('abc'));
console.log(stringCompression('xyz'));
console.log(stringCompression('AabBcC'));
console.log(stringCompression('cooool'));

```

## output

```console
a2b1c5a3
abc
xyz
AabBcC
c1o4l1
```

Implement a method to perform basic string compression using the counts of repeated characters.

String Compression Program

## Problem

 * One Away
 * These are types of edits that can be performed on strings
 * 1. insert a character
 * 2. remove a character
 * 3. replace a character
 * Given two strings, write a function to check if they are one edit (or zero) away.

## Program

```js
function oneAway(str1, str2) {
    let set = new Set();

    for (let char of str1) {
        set.add(char);
    }

    for (let char of str2) {
        set.delete(char);
    }

    const diff = set.size;
    if (diff === 0 || diff === 1) {
        return true;
    }

    return false;
}
```

## Output

```js
console.log(oneAway('pale', 'ple'));
console.log(oneAway('pales', 'pale'));
console.log(oneAway('pale', 'bale'));
console.log(oneAway('pale', 'bake'));
```

* One Away
 * These are types of edits that can be performed on strings
 * 1. insert a character
 * 2. remove a character
 * 3. replace a character
 * Given two strings, write a function to check if they are one edit (or zero) away.

String One Away Program

## Problem
 * Palindrome Permutation
 * Given a string, write a function to check if it is 
 * permutation of a palindrom.
 * A palindrome is a word or phases that is the same forwards and backwards.
 * A permutation is a rearrangement of letters.
 * The palindrome does not need to be limited to just dictionary word

## Code


```
/**
 * Palindrome Permutation
 * Given a string, write a function to check if it is 
 * permutation of a palindrom.
 * A palindrome is a word or phases that is the same forwards and backwards.
 * A permutation is a rearrangement of letters.
 * The palindrome does not need to be limited to just dictionary word
 */

function isPalindrome(str) {
    const strLength = str.length;

    for (let i = 0; i < strLength / 2; i++) {
        if (str[i] !== str[strLength - 1 - i]) {
            return false;
        }
    }

    return true;
}

console.log(isPalindrome('tacocat'));
console.log(isPalindrome('atcocta'));
console.log(isPalindrome('notapalindrom'));

```

## Output

```
true
true
false
```



Palindrome Permutation, Given a string, writes a function to check if it is a permutation of a palindrome.

Palindrome Permutation, Given a string, write a function to check if it is permutation of a palindrom.

## Problem

 Is Unique: Implement an algorithm to determine if a string has all unique characters,
 what if you cannot use additional data structure?
 Assume that string only contains the lowercase letter
 
## Program

```js
 function isUniqueCharacters(str) {
    
    let checker = 0;

    // loop through the string and store it to set
    for (let i=0; i<str.length; i++) {

        let val = str.charCodeAt(i) -  97; // 97 - 'a'.charCodeAt(0)
        let bitVal = 1 << val;

        if ((checker & bitVal) > 0) {
            return false;
        }
        else {
            checker = checker | bitVal;
        }
    }

    return true;
}
```

## Output

```bash
console.log(isUniqueCharacters('javascript'));
console.log(isUniqueCharacters('question'));

/**
 * Sample Input 1: javascript
 * Sample Output 1: false
 * 
 * Sample Input 2: question
 * Sample Output 2: true
 */
```

### Source Code

https://github.com/Aravin/dsa/blob/main/javascript/1_1.js

Implement an algorithm to determine if a string has all unique characters with the bitwise operator

Implement an algorithm to determine if a string has all unique characters with bitwise operator

## Program

```javascript
/**
 * Is Unique: Implement an algorithm to determine if a string has all unique characters,
 */
function isUniqueCharacters(str) {
    
    // using set to store only unique chars
    let set = new Set();

    // loop through the string and store it to set
    for (let i=0; i<str.length; i++) {
        set.add(str[i]);
    }

    return str.length === set.size ? true : false
}
```

## Sample Output

```js
console.log(isUniqueCharacters('javascript'));
console.log(isUniqueCharacters('question'));

/**
 * Sample Input 1: javascript
 * Sample Output 1: false
 * 
 * Sample Input 2: question
 * Sample Output 2: true
 */
```

### Source Code

https://github.com/Aravin/dsa/blob/main/javascript/1.js


Implement an algorithm to determine if a string has all unique characters

This is a tutorial to integrate CCAvenue Payment gateway to your website. Please follow the steps carefully for proper integration.
<h3>Prerequisites:</h3>
<ul>
 	<li>Active CCAvenue account.
– Merchant ID
– Access Code
– Secret or Encryption or Working Key</li>
 	<li>Integration kit from CCAvenue website.</li>
 	<li>Whitelist your domain/localhost</li>
 	<li>Any text editor. (VS Code Editor Prefered)</li>
</ul>
<h2>1. Account &amp; Domain</h2>
If you're testing in your local environment, you must add your localhost to your CCAvenue account. Also, make sure the valid port number is provided to CCAvenue for whitelisting.

<strong>Example</strong>:
If your localhost URL is you<code>http://localhost:55181/</code> should have Access code &amp; working key for this domain, not your main domain which you're using for production. Many people use to forget this.
If you whitelisted localhost:1234 and if you're using localhost:1235 or some other port number will not work. Please make sure the testing URL matches your CCAVenue details. Please find the screenshot below for more details.

![ccavene-integration-using-nodejs-express-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/ccavene_integration_using_nodejs_express_1_8e31d8c51f.png)


<h2>2. Download Integration Kit</h2>
Login into you CCAvenue account. Then go to Resources -&gt; Web Integration Kit -&gt; Download Integration kit &amp; then choose “Download Node.js as shown in the image below.

![ccavene-integration-using-nodejs-express-4-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/ccavene_integration_using_nodejs_express_4_1_a24acb18ac.png)


&nbsp;
<blockquote>Also, I have attached working copy of the Node.js integration kit here:&nbsp;<a href="/uploads/CC_Avenue_Node_Js_Integration_Kit_1_f85a948a79.zip">CCAvenue-NodeJs-IntegrationKit</a></blockquote>
<h2>3. Choose the Integration Method</h2>
<strong>CCAvenue gives 3 different types of integration.</strong>
<ul>
 	<li>Billing Page (Non-Seamless)</li>
 	<li>iFrame Checkout</li>
 	<li>Checkout Form</li>
</ul>
In our tutorial, we are going to use Billing page method. In backend almost these 3 methods are same but front-end behaviors will vary. You can find more details about this integration method in the ccavenue website.
<h2>4. Setting up the project</h2>
Open the folder<code>nonseamless</code> and open it in any of your favorite editors. I prefer VSCode.
Open the project path in command prompt in windows | bash in mac os.
Install the dependencies using the following command <code>npm install</code> This command will install all the dependencies for the project to be up and running. You will find a new folder.<code>node_modules</code>
<h2>5. Changes to be done in files</h2>
1. Open the file and<code>ccavRequestHandler.js</code> replace with your working key and access code.
2. <code>ccavResponseHandler.js</code> - replace with your working key.
3. <code>dataFrom.html</code> - replace the merchant id &amp; success and redirect URL to your localhost URL.

Thanks all, you are ready to collect payment on your website.
<h2>6. Start the Node Server</h2>
From the root of the project, run the following command <code>node run_node.js</code> which will run the node server from the file <code>run_node.js</code>
<h2>7. Test the integration</h2>
Browse the URL: localhost:/about. You will be on the following page.

![ccavene-integration-using-nodejs-express-2-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/ccavene_integration_using_nodejs_express_2_1_c50a41f5b9.png)

![ccavene-integration-using-nodejs-express-3-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/ccavene_integration_using_nodejs_express_3_1_9a1888bed4.png)

<h3>Download the working integration kit</h3>
<a href="/uploads/CC_Avenue_Node_Js_Integration_Kit_1_f85a948a79.zip">CCAvenue-NodeJs-IntegrationKit</a>



All the best :) For any clarification please write your comments below..

Steps to integrate CCAvenue Payment gateway to your website using Node.js - Express Framework (with Screenshot)

List of CCAvenue Response Parameters & Error Codes

Hi All, this tutorial is about CCAvenue payment gateway integration for ASP.NET Razor website (.CSHTML). If you are using ASP.NET web pages (.ASPX) you can check the tutorial <a href="/">here</a>.
<h2>Pre-Requisites</h2>
<ol>
 	<li>Visual Studio 2012 or&nbsp;Latest</li>
 	<li>CCAvenue Active account with
<ol>
 	<li>Merchant ID</li>
 	<li>Encryption Key</li>
 	<li>Access Code</li>
</ol>
</li>
 	<li>CCAvenue Integration Kit for ASP.NET</li>
 	<li>Custom ASP.NET Integration Kit for Razor (Download here:&nbsp;<a href="https://res.cloudinary.com/aravin/raw/upload/v1629652225/CC_Avenue_ASPNET_Razor_Kit_1_3_65d2691a74.zip">ccavenue_aspnet_razor_kit_1</a>)</li>
</ol>
<h2>Steps for Integration</h2>
<h3>1. Download Custom ASP.NET Integration Kit for Razor</h3>
Download the ASP.NET Integration Kit for Razor from the above link and import into your project. [<a href="https://res.cloudinary.com/aravin/raw/upload/v1629652225/CC_Avenue_ASPNET_Razor_Kit_1_3_65d2691a74.zip">Download Now</a>]
<h3>2. Adding reference to the project</h3>
<code>Download the CCAvenue Integration kit and&nbsp;add Right click on your visual studio project -&gt; Add -&gt; Reference&nbsp;</code>and choose the reference file <code>MCPG.CCA.Util.dll</code> and import it into the visual studio project.

![cca_reference-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/cca_reference_1_0aeed31caa.png)

<h3>3. Adding Access Code, Encryption and Merchant ID</h3>
Add Working key and Merchant ID to <strong>index.cshml</strong> file.
<blockquote>Search for&nbsp;Snippet
<pre class="">string&nbsp;workingKey&nbsp;=&nbsp;"add_your_32_bit_working_key_here";

</pre>
Replace with&nbsp;your 32 secret key given from CCAvenue</blockquote>
Add Working Key, Access Code to <strong>processor.chtml</strong> file.
<blockquote>Search for&nbsp;Snippet
<pre class="">var&nbsp;workingKey&nbsp;=&nbsp;"add_your_32_bit_working_key_here";
</pre>
and&nbsp;Snippet
<pre class="">var&nbsp;strAccessCode&nbsp;=&nbsp;"add_your_access_key_here";
</pre>
Replace with your working key and access key.</blockquote>
<h3>4. Set Test/Production environment</h3>
Open <code>processor.cshtml</code> and change form action as following,

<strong>For Testing</strong>,&nbsp;<code>https://test.ccavenue.com/transaction/transaction.do?command=initiateTransaction</code>

<strong>For Release,</strong>&nbsp;<code>https://secure.ccavenue.com/transaction/transaction.do?command=initiateTransaction</code>

![cca_environment-1.jpeg](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/cca_environment_1_56cc2fecd8.jpeg)


<h3>5. Build &amp; Run the project</h3>
i. Clean the project.

ii. Build the Project.

iii. Run the Project.

<hr>
<p style="text-align: center;">That's all :)</p>
<p style="text-align: left;">if you did all the steps as mentioned, you will get the website as shown below</p>

![cca_checkout_page-1.jpeg](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/cca_checkout_page_1_0c1595ab0d.jpeg)

Once you filled out this form, you will redirect to CCAvenue checkout page. Kindly drop your concern/issues/suggestion in below comment section.

How to integrate CCAvenue payment gateway into ASP.NET Razor website? (with steps & screenshots)

As we&nbsp;all know, SHA is an Cryptography hash function that is very much similar to <a title="How to encrypt plan text into md5 hash in C# program" href="http://aravin.net/how-to-encrypt-plan-text-into-md5-hash-in-csharp-program/" target="_blank" rel="noopener noreferrer">MD5 hashes</a>. SHA stands for Secure Hash Algorithm,. There are different versions in SHA like SHA-0, SHA-1, SHA-2, and SHA-3.

We are going to write program about SHA1 hash using C# code. &nbsp;We should know some basic thing about SHA1 before getting into code. So here are the some basic thing about SHA1,

1. It is an Hash Function.

2. It produce 160 bit&nbsp;output (20 Byte).

3. Output will be 20 digit (Hexadecimal value)
<h3>Here is the program for SHA1 using C#:</h3>
<pre class="lang:c# decode:true" title="SHA1 Hash program C#">using System;
using System.Security.Cryptography;
using System.Text;

namespace sha
{
    class Program
    {
        static void Main(string[] args)
        {

            string plain, hash;
            byte[] temp;

            plain = "Value to be hashed";

            SHA1 sha = new SHA1CryptoServiceProvider();
            // This is one implementation of the abstract class SHA1.
            temp = sha.ComputeHash(Encoding.UTF8.GetBytes(plain));


            //storing hashed vale into byte data type
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i &lt; temp.Length; i++)
                 {
                    sb.Append(temp[i].ToString("x2"));
                  }

            hash = sb.ToString();


            Console.WriteLine(hash);
            Console.ReadKey();
        }
    }
}
</pre>
The above code will generate the following output.

<span class="lang:c# decode:true  crayon-inline ">21d90aad4d34f48f4aad9b5fa3c37c118af16df9</span>

Same SHA1 hash Program using Input from User:
<pre class="lang:c# decode:true " title="SHA1 Hash function C# from user input">using System;
using System.Security.Cryptography;
using System.Text;

namespace sha
{
    class Program
    {
        static void Main(string[] args)
        {

            string plain, hash;
            byte[] temp;

            Console.WriteLine("Enter any value : ");
            plain = Console.ReadLine();

            SHA1 sha = new SHA1CryptoServiceProvider();
            // This is one implementation of the abstract class SHA1.
            temp = sha.ComputeHash(Encoding.UTF8.GetBytes(plain));


            //storing hashed vale into byte data type
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i &lt; temp.Length; i++)
                 {
                    sb.Append(temp[i].ToString("x2"));
                  }

            hash = sb.ToString();


            Console.WriteLine(hash);
            Console.ReadKey();
        }
    }
}
</pre>
You can write your comments below.

How to encrypt plain text into SHA1 hash using C# program?

### Steps to align textbox and label

Step 1: Center a <code>div</code> tag using margin as `0 auto`.

Step 2: Align the <code>label</code> to <code>right</code> and make it <code>float</code> to <code>left</code>.

Step 3: Align the <code>textbox</code> to <code>lef</code>t and make it <code>float</code> to <code>right</code>.

Step 4: Make both label and textbox to <code>inline-block</code>.

### HTML  &amp; CSS

```html
<!DOCTYPE html>
<html>
<head>
	<title>Centering a form</title>
</head>
<body>
	<div class="form">
		<label>Name</label>
		<input type="text" name="name">

		<label>Email</label>
		<input type="text" name="email">

		<label>Phone</label>
		<input type="text" name="phone">
	</div>
</body>
</html>

<style type="text/css">
	.form {
		margin: 0 auto;
		width: 210px;
	}

	.form label{
		display: inline-block;
		text-align: right;
		float: left;
	}

	.form input{
		display: inline-block;
		text-align: left;
		float: right;
	}
</style>
```

### Live demo here: https://jsfiddle.net/durtpwvx/

How to center align the label and the textbox in HTML horizontally in webpage

<h2>Install xml2js</h2>
<code>npm install xml2js
npm install @types/xml2js --save-dev</code>
<h2>Program

```
    import { parseString, Builder } from "xml2js";

    // Convert string/XML to JSON
    function toJson(xml: string) {

        parseString(xml, { explicitArray: false }, function(error, result) {
            console.log(result);
        });
    }

    // Convert string/JSON to XML
    function toXML(json: string) {

        const builder = new Builder();
        console.log(builder.buildObject(json));
    }


    // Test Data
    const employeeJson: any = {
        Employee: {
            name: 'Aravind',
            age: 24,
            sex: 'Male'
        
    }
    };

    const employeeXml = "<Employee><name>Aravind</name><age>24</age><sex>Male</sex></Employee>"


    // Result
    toJson(employeeXml);
    toXML(employeeJson);


////
/// SAMPLE OUTPUT 
////

{ Employee: { name: 'Aravind', age: '24', sex: 'Male' } }

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Employee>
  <name>Aravind</name>
  <age>24</age>
  <sex>Male</sex>
</Employee>
    
```

Converting JSON toXML& XML to JSON in Node.js using xml2js package in TypeScript

<h3>CCAvenue Response Codes</h3>
<table width="621">
<tbody>
<tr>
<td width="115">Name</td>
<td width="363">Description</td>
<td width="143">Type (length)</td>
</tr>
<tr>
<td width="115">order_id</td>
<td width="363">Unique ID sent by the merchant at the time of initiating the transaction.</td>
<td width="143">Alphanumeric (30)</td>
</tr>
<tr>
<td width="115">tracking_id</td>
<td width="363">Unique payment reference number generated by CCAvenue for each order.</td>
<td width="143">Numeric (12)</td>
</tr>
<tr>
<td width="115">bank_ref_no</td>
<td width="363">Reference number generated by the bank for the transaction.</td>
<td width="143">Alphanumeric</td>
</tr>
<tr>
<td rowspan="5" width="115">order_status</td>
<td width="363">Status of the transaction.</td>
<td rowspan="5" width="143">Alphabets (15)</td>
</tr>
<tr>
<td width="363">Success</td>
</tr>
<tr>
<td width="363">Failure</td>
</tr>
<tr>
<td width="363">Aborted</td>
</tr>
<tr>
<td width="363">Invalid</td>
</tr>
<tr>
<td width="115">failure_message</td>
<td width="363">Reason for failure.</td>
<td width="143">Alphanumeric</td>
</tr>
<tr>
<td rowspan="6" width="115">payment_mode</td>
<td width="363">Mode of payment used by the customer</td>
<td rowspan="6" width="143">Alphabets</td>
</tr>
<tr>
<td width="363">Credit Card</td>
</tr>
<tr>
<td width="363">Net banking</td>
</tr>
<tr>
<td width="363">Debit Card</td>
</tr>
<tr>
<td width="363">Cash Card</td>
</tr>
<tr>
<td width="363">Mobile Payment</td>
</tr>
<tr>
<td width="115">card_name</td>
<td width="363">The name of the card/bank used by the customer to make the payment. Credit Card - Visa, Mastercard, Amex Netbanking - ICICI, HDFC, SBI etc.</td>
<td width="143">Alphanumeric</td>
</tr>
<tr>
<td width="115">status_code</td>
<td width="363">Authorization code received from the bank.</td>
<td width="143">Numeric (3)</td>
</tr>
<tr>
<td width="115">status_message</td>
<td width="363">Authorization status message received from the bank.</td>
<td width="143">Alphanumeric (150)</td>
</tr>
<tr>
<td rowspan="6" width="115">currency</td>
<td width="363">Currency code in which the transaction was processed.</td>
<td rowspan="6" width="143">Alphabets (3)</td>
</tr>
<tr>
<td width="363">INR - Indian Rupee</td>
</tr>
<tr>
<td width="363">USD - United States Dollar</td>
</tr>
<tr>
<td width="363">SGD - Singapore Dollar</td>
</tr>
<tr>
<td width="363">GBP - Pound Sterling</td>
</tr>
<tr>
<td width="363">EUR - Euro, official currency of Eurozone</td>
</tr>
<tr>
<td width="115">amount</td>
<td width="363">Order amount</td>
<td width="143">Numeric (12, 2)</td>
</tr>
<tr>
<td width="115">billing_ name</td>
<td width="363">Name of the customer</td>
<td width="143">Alphabets (60)</td>
</tr>
<tr>
<td width="115">billing_ address</td>
<td width="363">Customer's billing address</td>
<td width="143">Alphanumeric (150)</td>
</tr>
<tr>
<td width="115">billing_ city</td>
<td width="363">Customer's billing city</td>
<td width="143">Alphabets (30)</td>
</tr>
<tr>
<td width="115">billing_ state</td>
<td width="363">Customer's billing state</td>
<td width="143">Alphabets (30)</td>
</tr>
<tr>
<td width="115">billing_ zip</td>
<td width="363">Customer's billing zip code</td>
<td width="143">Alphanumeric (15)</td>
</tr>
<tr>
<td width="115">billing_ country</td>
<td width="363">Customer's billing country</td>
<td width="143">Alphabets (50)</td>
</tr>
<tr>
<td width="115">billing_ tel</td>
<td width="363">Customer's phone number</td>
<td width="143">Numeric (20)</td>
</tr>
<tr>
<td width="115">billing_ email</td>
<td width="363">Customer's email address</td>
<td width="143">Alphanumeric (70)</td>
</tr>
<tr>
<td width="115">delivery_ name</td>
<td width="363">Recipient's name</td>
<td width="143">Alphabets (60)</td>
</tr>
<tr>
<td width="115">delivery_ address</td>
<td width="363">Shipping address</td>
<td width="143">Alphanumeric (150)</td>
</tr>
<tr>
<td width="115">delivery_ city</td>
<td width="363">Shipping city</td>
<td width="143">Alphabets (30)</td>
</tr>
<tr>
<td width="115">delivery_ state</td>
<td width="363">Shipping state</td>
<td width="143">Alphabets (30)</td>
</tr>
<tr>
<td width="115">delivery_ zip</td>
<td width="363">Shipping zip code</td>
<td width="143">Alphanumeric (15)</td>
</tr>
<tr>
<td width="115">delivery_ country</td>
<td width="363">Shipping country</td>
<td width="143">Alphabets (50)</td>
</tr>
<tr>
<td width="115">delivery_ tel</td>
<td width="363">Shipping phone number</td>
<td width="143">Numeric (22)</td>
</tr>
<tr>
<td width="115">merchant_param1</td>
<td width="363">Additional information about the transaction sent by the merchant.</td>
<td width="143">Alphanumeric (100)</td>
</tr>
<tr>
<td width="115">merchant_param2</td>
<td width="363">Additional information about the transaction sent by the merchant.</td>
<td width="143">Alphanumeric (100)</td>
</tr>
<tr>
<td width="115">merchant_param3</td>
<td width="363">Additional information about the transaction sent by the merchant.</td>
<td width="143">Alphanumeric (100)</td>
</tr>
<tr>
<td width="115">merchant_param4</td>
<td width="363">Additional information about the transaction sent by the merchant.</td>
<td width="143">Alphanumeric (100)</td>
</tr>
<tr>
<td width="115">merchant_param5</td>
<td width="363">Additional information about the transaction sent by the merchant.</td>
<td width="143">Alphanumeric (100)</td>
</tr>
<tr>
<td width="115">vault</td>
<td width="363">This parameter can be used if merchant availing the vault option. On using vault functionality if card details are saved at CCAvenue end value returned will be Y. If card details are not saved at CCAvenue end the value returned for this parameter will be N.</td>
<td width="143">Character (1)</td>
</tr>
<tr>
<td width="115">offer_type</td>
<td width="363">This parameter can be used for sending additional information if customer has used any discount or promotion while completing the transaction. If customer is using discount-coupon, value of this parameter would be discount. If customer is using promo-code, value of this parameter would be promotion.</td>
<td width="143">Alphabets (9)</td>
</tr>
<tr>
<td width="115">offer_code</td>
<td width="363">This parameter can be used for sending additional information about the discount coupon and Promo code used while completing the transaction. If customer has used Discount the value sent would be Discount code. If customer has used Promotion the value sent would be Promo code.</td>
<td width="143">Alphanumeric (30)</td>
</tr>
<tr>
<td width="115">discount_value</td>
<td width="363">This parameter can be used for sending additional information about the discounted amount.</td>
<td width="143">Numeric (12,2)</td>
</tr>
<tr>
<td rowspan="5" width="115">retry</td>
<td width="363">This denotes whether the transaction is a retry transaction or not.</td>
<td rowspan="5" width="143">Character (1)</td>
</tr>
<tr>
<td width="363">Value:</td>
</tr>
<tr>
<td width="363">Y - Retry Transaction</td>
</tr>
<tr>
<td width="363">N - Not a Retry Transaction</td>
</tr>
<tr>
<td width="363">Note:&nbsp;A transaction done for the first time would be marked as 'N', whereas the subsequent valid retry attempts would be marked as 'Y'.</td>
</tr>
<tr>
<td width="115">response_code</td>
<td width="363">This is the code assigned to each type of response received from the bank.</td>
<td width="143">Numeric (5)</td>
</tr>
</tbody>
</table>

Complete list of CCAvenue Response code with description


<h2>About this tutorial</h2>
This is an end-to-end guide to integrating a CCAvenue payment gateway into ASP.NET web application using official kit. Starting from account setup to successful payment.
<h2>Pre-Requirement</h2>
<ol>
 	<li>Visual Studio</li>
 	<li>Active CCAvenue account
<ol>
 	<li>Merchant ID</li>
 	<li>Access Code</li>
 	<li>Working Key</li>
</ol>
</li>
 	<li>Official CCAvenue kit</li>
 	<li>Little knowledge about C# &amp; ASP.NET</li>
</ol>
<h3></h3>
<h3>Setting up your CCAvenue account for localhost</h3>
In order to run your CCAvenuepayment gateway in localhost, we need to add our localhost into CCAvenue account. You have to write an email to <code>service@ccavenue.com</code> and ask him to add your localhost. &nbsp;Kindly refer screenshot below for more details.

<strong>Example</strong>: http://localhost:55181/
<h4>Screenshot 1</h4>

![CCAvenue-Integration-Guide-2-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/CC_Avenue_Integration_Guide_2_1_e9173aa429.png)


<h3></h3>
<h3>Download Integration Kit from CCAvenue website</h3>
Integration kit will be available on http://ccavenue.com → Resources → Web Integration Kit → Download Integration Kit → Download ASP.NET 3.5

![CCAvenue-Integration-Guide-3-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/CC_Avenue_Integration_Guide_3_1_6de90cb895.png)

Also, you can download from here:&nbsp;<a href="https://res.cloudinary.com/aravin/raw/upload/v1629651987/ASP_Net_Kit_Version_3_5_1_1ebd67b9ab.zipthe ">ASP.Net_Kit_Version_3.5</a>


<h3>Extract the Integration Kit</h3>


<h3>Open the Project in Visual Studio</h3>
<ol>
 	<li>Open Visual Studio</li>
 	<li>Choose Open&nbsp;→ Project/Solution from the file menu.</li>
</ol>

![CCAvenue-Integration-Guide-5-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/CC_Avenue_Integration_Guide_5_1_a5bd98de1e.png)

3. Browse to the downloaded Integration kit. Open the <code>NON-SEAMLESS KIT</code>

![CCAvenue-Integration-Guide-6-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/CC_Avenue_Integration_Guide_6_1_adb7d4c73b.png)


4. Open <code>MCPG.ASP.net.ENC</code>

![CCAvenue-Integration-Guide-7-2.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/CC_Avenue_Integration_Guide_7_2_88c5aa22be.png)


<h3></h3>
<h3>Add Reference to the project [Very Important]</h3>
Many people used to face an issue in this stage. But it is really an easy step. Kindly follow the screenshot.

Right-click the References in solution explorer →&nbsp;Add Reference

![CCAvenue-Integration-Guide-8-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/CC_Avenue_Integration_Guide_8_1_4746e10cd7.png)

<blockquote>Note: Reference DLL file will be available in downloaded integration kit itself.</blockquote>
Browse the downloaded folder
<ol>
 	<li>bin → MCPG.ASP.net.ENC.dll &amp; add it to the project.</li>
 	<li>lib&nbsp;→ MCPG.CCA.Util.dll &amp; add it to project.</li>
</ol>
<blockquote>Note: REMOVE existing dll, if any. You have to add fresh dll.</blockquote>
<h3></h3>
<h3>Add localhost to the project</h3>
This step is mandatory to run the CCAvenue&nbsp;setup in local system i.e in a development system. If you didn't ask localhost, this setup won't work because by default asp.net project will point to&nbsp;some default IP like&nbsp;<code>http://127.0.0.1/</code>

So, better add your localhost i.e In my case it is which&nbsp;<code>http://localhost:55181/</code> is same as in my CCAvenue Account, which we have added in step 1.
<blockquote>Right click project&nbsp;→ Properties</blockquote>
![CCAvenue-Integration-Guide-10-1.png](https://res.cloudinary.com/aravin/image/upload/v1629651261/CC_Avenue_Integration_Guide_10_1_d723bec42c.png)


<h3>Change Merchant ID, Acess Code and Working Key in our application</h3>
<strong>Pages to be modified:-</strong>
<ol>
 	<li>ccavRequestHandler.aspx.cs</li>
 	<li>ccavResponseHandler.aspx.cs</li>
 	<li>dataFrom.htm</li>
</ol>
Change workingKey and&nbsp;strAccessCode in&nbsp;ccavRequestHandler.aspx.cs
![CCAvenue-Integration-Guide-11-1.png](https://res.cloudinary.com/aravin/image/upload/v1629651263/CC_Avenue_Integration_Guide_11_1_59b110868b.png)



Change workingKey again in &nbsp;ccavResponseHandler.aspx.cs

![CCAvenue-Integration-Guide-12-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/CC_Avenue_Integration_Guide_12_1_966bcf8cbb.png)


Change&nbsp;merchant_id,&nbsp;redirect_url,&nbsp;cancel_url - VERY IMPORTANT

![CCAvenue-Integration-Guide-13-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/CC_Avenue_Integration_Guide_13_1_b267fab24e.png)



<h4>Great :) If you followed all the step, you can build &amp; run</h4>
<h3>Choose between Testing/Live environment</h3>
You can choose Testing or Live environment from the&nbsp;<code>ccavRequestHandler.aspx</code>

<strong>For Live Environment&nbsp;</strong>
<pre>https://secure.ccavenue.com/transaction/transaction.do?command=initiateTransaction
</pre>
<strong>For Testing Environment</strong>
<pre>https://test.ccavenue.com/transaction/transaction.do?command=initiateTransaction
</pre>
<h3>Making Payment in Live (Production) Environment</h3>
Run the application, you will see the following account.

![CCAvenue-Integration-Guide-15-1-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/CC_Avenue_Integration_Guide_15_1_1_cac29ac52f.png)

Fill the details &amp; Proceed to checkout

Choose the preferred&nbsp;payment gateway from Credit Card/Debit Card/Net Baking etc..

Enter the required details and click on make payment

![CCAvenue-Integration-Guide-17-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/CC_Avenue_Integration_Guide_17_1_4e9e263a76.png)


<strong>Finally, Complete the payment :)</strong>

![CCAvenue-Integration-Guide-18-1.png](https://aravin-net-cms.s3.ap-south-1.amazonaws.com/CC_Avenue_Integration_Guide_18_1_ee85909703.png)

That's all :) You can push your code to Live Website :)

I tried my best to cover all the steps in screenshot &amp; steps. If I missed any steps, kindly drop the queries in a comment section.

Also, for any clarification or doubt, please write back to me on comment section. I will try to reply as soon as possible.

Complete guide to integrate CCAvenue Payment gateway into ASP.NET website - with Screenshot

## Problem

Check Permutation: Given two strings, write a method to decide if one is a permutation of the other

## Code

```js
/** Check Permutation: Given two strings,
 * write a method to decide if one is a permutation of the other
 */

function checkPermutation(str1, str2) {

    const set = new Set();

    if (str1.length !== str2.length) {
        return false;
    }

    for (let i = 0; i < str1.length; i++) {
        const index = str2.indexOf(str1[i]);

        if (index === -1 || set.has(index)) {
            return false;
        } else {
            set.add(index);
        }
    }

    return true;
}

```


## Sample Output:

```js
console.log(checkPermutation('one', 'neo'));
console.log(checkPermutation('abc', 'xyz'));
console.log(checkPermutation('zeroo', 'heroz'));

/** Sample Output
 * true
 * false
 * false
 */
```


Check Permutation: Given two strings, write a method to decide if one is a permutation of the other

Implement an algorithm to Check Permutation of two strings

I code using JavaScript, TypeScript, Node.js, C#, and dart. I write articles, youtube videos, and open source contributions. I develop mobile (Android and iOS), web and desktop applications.