Caesar Cipher – Hackerrank Challenge – C# Solution
This is the c# solution for the Hackerrank problem – Caesar Cipher – Hackerrank Challenge – C# Solution.
Source – Ryan Fehr’s repository.
/*
Problem: https://www.hackerrank.com/challenges/caesar-cipher-1/problem
C# Language Version: 6.0
.Net Framework Version: 4.7
Tool Version : Visual Studio Community 2017
Thoughts :
- we only have to process a character in the input text if it is an alphabet else print it directly on console.
- produce the encoded character for each alphabet in input text by moving it in the alphabet series shift factor steps.
- A cautionary step is when the shift factor is > 26. If it is the case then get the shift factor by doing a modulus
so that it becomes <= 26.
Time Complexity: O(n) //iteration of whole input text is required once.
Space Complexity: O(n) //we need to store the entire input text in memory to process it.
*/
using System;
class Solution
{
static void Main(string[] args)
{
//No need to capture the size of string. We can use string's length property instead.
Console.ReadLine();
var inputText = Console.ReadLine();
var shiftFactor = int.Parse(Console.ReadLine());
if (shiftFactor > 26)
shiftFactor = shiftFactor % 26;
for (var i = 0; i < inputText.Length; i++)
{
var asciiCode = (int)inputText[i];
if (asciiCode <= 122 && asciiCode > 96)
{
//small case alphabets
if (asciiCode + shiftFactor <= 122)
//we're within range. Replace the encoded character
Console.Write((char)(((int)inputText[i]) + shiftFactor));
else
{
var offset = shiftFactor - (122 - asciiCode);
Console.Write((char)(96 + offset));
}
}
else if (asciiCode <= 90 && asciiCode > 64)
{
//upper case alphabets
if (asciiCode + shiftFactor <= 90)
//we're within range. Replace the encoded character
Console.Write((char)(((int)inputText[i]) + shiftFactor));
else
{
var offset = shiftFactor - (90 - asciiCode);
Console.Write((char)(64 + offset));
}
}
else
Console.Write(inputText[i]);
}
}
}
