To rotate array elements left/right

Sandhiya Priya
4d
191
0
1

Article

Step 1: Design Page – RotateArray.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="RotateArray.aspx.cs" Inherits="RotateArray" %>

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Rotate Array Elements - Real Time Example</title>
    <style>
        body {
            font-family: Arial;
            background-color: #f4f7fc;
            margin: 50px;
        }
        .container {
            width: 550px;
            margin: auto;
            background: #fff;
            border-radius: 10px;
            box-shadow: 0px 0px 10px #ccc;
            padding: 25px;
        }
        h2 {
            color: #1A2A80;
            text-align: center;
        }
        .form-control {
            width: 100%;
            padding: 8px;
            margin-top: 10px;
        }
        .btn {
            background-color: #7A85C1;
            color: white;
            border: none;
            padding: 10px;
            border-radius: 5px;
            cursor: pointer;
            margin-top: 10px;
            width: 48%;
        }
        .btn:hover {
            background-color: #5d66a1;
        }
        .result {
            margin-top: 20px;
            font-weight: bold;
            color: #333;
            text-align: center;
            white-space: pre-line;
        }
        .button-group {
            display: flex;
            justify-content: space-between;
        }
    </style>
</head>
<body>
    <form id="form1" runat="server">
        <div class="container">
            <h2>Rotate Array Elements (Left / Right)</h2>

            <asp:Label ID="lblInput" runat="server" Text="Enter Array Elements (comma-separated):"></asp:Label><br />
            <asp:TextBox ID="txtNumbers" runat="server" CssClass="form-control" placeholder="Example: 10, 20, 30, 40, 50"></asp:TextBox><br />

            <asp:Label ID="lblRotate" runat="server" Text="Enter Number of Rotations:"></asp:Label><br />
            <asp:TextBox ID="txtRotateCount" runat="server" CssClass="form-control" placeholder="Example: 2"></asp:TextBox><br />

            <div class="button-group">
                <asp:Button ID="btnLeft" runat="server" Text="Rotate Left" CssClass="btn" OnClick="btnLeft_Click" />
                <asp:Button ID="btnRight" runat="server" Text="Rotate Right" CssClass="btn" OnClick="btnRight_Click" />
            </div>

            <asp:Label ID="lblResult" runat="server" CssClass="result"></asp:Label>
        </div>
    </form>
</body>
</html>

Step 2: Backend Logic – RotateArray.aspx.cs

using System;
using System.Linq;

public partial class RotateArray : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
    }

    // Rotate Left Button Click
    protected void btnLeft_Click(object sender, EventArgs e)
    {
        RotateArrayElements("Left");
    }

    // Rotate Right Button Click
    protected void btnRight_Click(object sender, EventArgs e)
    {
        RotateArrayElements("Right");
    }

    private void RotateArrayElements(string direction)
    {
        try
        {
            string input = txtNumbers.Text.Trim();
            int rotateCount = Convert.ToInt32(txtRotateCount.Text.Trim());

            if (string.IsNullOrEmpty(input))
            {
                lblResult.Text = "Please enter array elements.";
                lblResult.ForeColor = System.Drawing.Color.Red;
                return;
            }

            int[] numbers = input.Split(',').Select(x => Convert.ToInt32(x.Trim())).ToArray();
            int n = numbers.Length;

            if (rotateCount < 0)
            {
                lblResult.Text = "Rotation count cannot be negative.";
                lblResult.ForeColor = System.Drawing.Color.Red;
                return;
            }

            rotateCount = rotateCount % n; // handle large rotations

            int[] rotated = new int[n];

            if (direction == "Left")
            {
                for (int i = 0; i < n; i++)
                {
                    rotated[i] = numbers[(i + rotateCount) % n];
                }
            }
            else // Right rotation
            {
                for (int i = 0; i < n; i++)
                {
                    rotated[(i + rotateCount) % n] = numbers[i];
                }
            }

            lblResult.Text = $"Original Array: {string.Join(", ", numbers)}\n" +
                             $"{direction} Rotated by {rotateCount}: {string.Join(", ", rotated)}";
            lblResult.ForeColor = System.Drawing.Color.Green;
        }
        catch
        {
            lblResult.Text = "Invalid input! Please enter valid numbers and rotation count.";
            lblResult.ForeColor = System.Drawing.Color.Red;
        }
    }
}

Real-Time Example Flow

Open the page RotateArray.aspx in your browser.
Enter:
```
10, 20, 30, 40, 50
```
and rotation count:
```
2
```

Click Rotate Left
Output

Original Array: 10, 20, 30, 40, 50
Left Rotated by 2: 30, 40, 50, 10, 20

Click Rotate Right
Output

Original Array: 10, 20, 30, 40, 50
Right Rotated by 2: 40, 50, 10, 20, 30

Explanation

Step	Description
1	User enters comma-separated numbers and number of rotations.
2	Program converts them into an integer array.
3	For left rotation: shift each element left by rotateCount.
4	For right rotation: shift each element right by rotateCount.
5	Display original and rotated arrays on the web page.

Example Input / Output Table

Input Array	Rotations	Direction	Output
10, 20, 30, 40, 50	2	Left	30, 40, 50, 10, 20
10, 20, 30, 40, 50	1	Right	50, 10, 20, 30, 40
5, 10, 15, 20	3	Left	20, 5, 10, 15
100, 200, 300	4	Right	200, 300, 100

Algorithm

1. Read array elements and rotation count.
2. If direction = Left:
      rotated[i] = arr[(i + count) % n]
   Else if direction = Right:
      rotated[(i + count) % n] = arr[i]
3. Print rotated array.