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Reverse alternate k characters in a string

Here given code implementation process.

//C Program
//Reverse alternate k characters in a string
#include <stdio.h>

//Reverse the substrings between given location
void reverse(char * text, int start, int end)
{
	if (start == end)
	{
		return;
	}
	char temp;
	//Reverse the string element from start to end location
	for (start; start < end; start++, end--)
	{
		temp = text[start];
		text[start] = text[end];
		text[end] = temp;
	}
}
//This function is reversing alternate groups of k characters
void reverse_alternate_char(char * text, int k, int size)
{
	if (k <= 0 || size <= 0)
	{
		return;
	}
	printf("\n Given String : %s\n", text);
	for (int i = 0; i <= size - k; i += k)
	{
		reverse(text, i, i + (k - 1));
		// skip group of k characters
		i += k;
	}
	printf(" Alternate Characters : %d\n", k);
}
int main()
{
	//Define the character elements
	char text1[] = "123ABC567EFG";
	//Get the size
	int size = sizeof(text1) / sizeof(text1[0]) - 1;
	//Get result
	reverse_alternate_char(text1, 3, size);
	printf(" After Result : %s\n", text1);
	// Other cases
	char text2[] = "12345ABCDE678";
	size = sizeof(text2) / sizeof(text2[0]) - 1;
	reverse_alternate_char(text2, 5, size);
	printf(" After Result : %s\n", text2);
	char text3[] = "1234ABCD1234ABCDEF";
	size = sizeof(text3) / sizeof(text3[0]) - 1;
	reverse_alternate_char(text3, 4, size);
	printf(" After Result : %s\n", text3);
	char text4[] = "ABCDEFGHIJKLMO";
	size = sizeof(text4) / sizeof(text4[0]) - 1;
	reverse_alternate_char(text4, 2, size);
	printf(" After Result : %s\n", text4);
	return 0;
}

Output

 Given String : 123ABC567EFG
 Alternate Characters : 3
 After Result : 321ABC765EFG

 Given String : 12345ABCDE678
 Alternate Characters : 5
 After Result : 54321ABCDE678

 Given String : 1234ABCD1234ABCDEF
 Alternate Characters : 4
 After Result : 4321ABCD4321ABCDEF

 Given String : ABCDEFGHIJKLMO
 Alternate Characters : 2
 After Result : BACDFEGHJIKLOM
//Java Program 
//Reverse alternate k characters in a string
class MyString
{
	//Reverse the substrings between given location
	//Returns reversal form of substring of given location
	public String reverse(String text, int start, int end)
	{
		if (start == end)
		{
			return "";
		}
		String result = "";
		//Reverse the string element from start to end location
		for (int i = start; i <=end ; i++)
		{
			result = text.charAt(i)+result;
		}
		return result;
	}
	//This function is reversing alternate groups of k characters
	public String reverse_alternate_char(String text, int k)
	{
		int size = text.length();

		if (k <= 0 || size <= 0)
		{
			return text;
		}
		//loop controlling variable [i]
		int i = 0;
		//This is store the resultant result
		String result = "";

		//This is used to detect reversal location
      	int counter = 0;

		System.out.print("\n Given String : " + text + "\n");
		
		//Loop iterating string elements
		for (i = 0; i < size ; i++)
		{
           	//Condition which is check valid reverse k characters elements
            if(counter==0 && i <= size - k)
            {
				result += reverse(text, i, i + (k - 1));
                
                counter = k;
            	
            	//Skip group of k-1 characters
                i = i + (k - 1);
            }
          	else
            {
              counter--;
              result += text.charAt(i);
            }
		}
		System.out.print(" Alternate Characters : " + k + "\n");
		return result;
	}
	public static void main(String[] args)
	{
		MyString obj = new MyString();
		String text = "123ABC567EFG";
		text = obj.reverse_alternate_char(text, 3);
		System.out.print(" After Result : " + text + "\n");
		text = "12345ABCDE678";
		text = obj.reverse_alternate_char(text, 5);
		System.out.print(" After Result : " + text + "\n");
		text = "1234ABCD1234ABCDEF";
		text = obj.reverse_alternate_char(text, 4);
		System.out.print(" After Result : " + text + "\n");
		text = "ABCDEFGHIJKLMO";
		text = obj.reverse_alternate_char(text, 2);
		System.out.print(" After Result : " + text + "\n");
	}
}

Output

 Given String : 123ABC567EFG
 Alternate Characters : 3
 After Result : 321ABC765EFG

 Given String : 12345ABCDE678
 Alternate Characters : 5
 After Result : 54321ABCDE678

 Given String : 1234ABCD1234ABCDEF
 Alternate Characters : 4
 After Result : 4321ABCD4321ABCDEF

 Given String : ABCDEFGHIJKLMO
 Alternate Characters : 2
 After Result : BACDFEGHJIKLOM
//Include header file
#include <iostream>
#include<string.h>
using namespace std;

//C++ Program 
//Reverse alternate k characters in a string
class MyString
{
	public:
		//Reverse the substrings between given location
		//Returns reversal form of substring of given location
		string reverse(string text, int start, int end)
		{
			if (start == end)
			{
				return "";
			}
			string result = "";
			//Reverse the string element from start to end location
			for (int i = start; i <= end; i++)
			{
				result = text[i] + result;
			}
			return result;
		}
	//This function is reversing alternate groups of k characters
	string reverse_alternate_char(string text, int k)
	{
		int size = text.size();
		if (k <= 0 || size <= 0)
		{
			return text;
		}
		//loop controlling variable [i,j]
		int i = 0;
		int j = 0;
		//This is store the resultant result
		string result = "";
		//This is used to detect reversal location
		int counter = 0;
		cout << "\n Given String : " << text << "\n";
		//Loop iterating string elements
		for (i = 0; i < size; i++)
		{
			//Condition which is check valid reverse k characters elements
			if (counter == 0 && i <= size - k)
			{
				result += this->reverse(text, i, i + (k - 1));
				counter = k;
				//Skip group of k-1 characters
				i = i + (k - 1);
			}
			else
			{
				counter--;
				result += text[i];
			}
		}
		cout << " Alternate Characters : " << k << "\n";
		return result;
	}
};
int main()
{
	MyString obj = MyString();
	string text = "123ABC567EFG";
	text = obj.reverse_alternate_char(text, 3);
	cout << " After Result : " << text << "\n";
	text = "12345ABCDE678";
	text = obj.reverse_alternate_char(text, 5);
	cout << " After Result : " << text << "\n";
	text = "1234ABCD1234ABCDEF";
	text = obj.reverse_alternate_char(text, 4);
	cout << " After Result : " << text << "\n";
	text = "ABCDEFGHIJKLMO";
	text = obj.reverse_alternate_char(text, 2);
	cout << " After Result : " << text << "\n";
	return 0;
}

Output

 Given String : 123ABC567EFG
 Alternate Characters : 3
 After Result : 321ABC765EFG

 Given String : 12345ABCDE678
 Alternate Characters : 5
 After Result : 54321ABCDE678

 Given String : 1234ABCD1234ABCDEF
 Alternate Characters : 4
 After Result : 4321ABCD4321ABCDEF

 Given String : ABCDEFGHIJKLMO
 Alternate Characters : 2
 After Result : BACDFEGHJIKLOM
//Include namespace system
using System;

//C# Program 
//Reverse alternate k characters in a string
class MyString
{
	//Reverse the substrings between given location
	//Returns reversal form of substring of given location
	public String reverse(String text, int start, int end)
	{
		if (start == end)
		{
			return "";
		}
		String result = "";
		//Reverse the string element from start to end location
		for (int i = start; i <= end; i++)
		{
			result = text[i] + result;
		}
		return result;
	}
	//This function is reversing alternate groups of k characters
	public String reverse_alternate_char(String text, int k)
	{
		int size = text.Length;
		if (k <= 0 || size <= 0)
		{
			return text;
		}
		//loop controlling variable [i]
		int i = 0;
		//This is store the resultant result
		String result = "";
		//This is used to detect reversal location
		int counter = 0;
		Console.Write("\n Given String : " + text + "\n");
		//Loop iterating string elements
		for (i = 0; i < size; i++)
		{
			//Condition which is check valid reverse k characters elements
			if (counter == 0 && i <= size - k)
			{
				result += reverse(text, i, i + (k - 1));
				counter = k;
				//Skip group of k-1 characters
				i = i + (k - 1);
			}
			else
			{
				counter--;
				result += text[i];
			}
		}
		Console.Write(" Alternate Characters : " + k + "\n");
		return result;
	}
	public static void Main(String[] args)
	{
		MyString obj = new MyString();
		String text = "123ABC567EFG";
		text = obj.reverse_alternate_char(text, 3);
		Console.Write(" After Result : " + text + "\n");
		text = "12345ABCDE678";
		text = obj.reverse_alternate_char(text, 5);
		Console.Write(" After Result : " + text + "\n");
		text = "1234ABCD1234ABCDEF";
		text = obj.reverse_alternate_char(text, 4);
		Console.Write(" After Result : " + text + "\n");
		text = "ABCDEFGHIJKLMO";
		text = obj.reverse_alternate_char(text, 2);
		Console.Write(" After Result : " + text + "\n");
	}
}

Output

 Given String : 123ABC567EFG
 Alternate Characters : 3
 After Result : 321ABC765EFG

 Given String : 12345ABCDE678
 Alternate Characters : 5
 After Result : 54321ABCDE678

 Given String : 1234ABCD1234ABCDEF
 Alternate Characters : 4
 After Result : 4321ABCD4321ABCDEF

 Given String : ABCDEFGHIJKLMO
 Alternate Characters : 2
 After Result : BACDFEGHJIKLOM
<?php
//Php Program 
//Reverse alternate k characters in a string
class MyString
{
	//Reverse the substrings between given location
	//Returns reversal form of substring of given location
	public	function reverse($text, $start, $end)
	{
		if ($start == $end)
		{
			return "";
		}
		$result = "";
		//Reverse the string element from start to end location
		for ($i = $start; $i <= $end; $i++)
		{
			$result = $text[$i] . $result;
		}
		return $result;
	}
	//This function is reversing alternate groups of k characters
	public	function reverse_alternate_char($text, $k)
	{
		$size = strlen($text);
		if ($k <= 0 || $size <= 0)
		{
			return $text;
		}
		//loop controlling variable [i]
		$i = 0;
		//This is store the resultant result
		$result = "";
		//This is used to detect reversal location
		$counter = 0;
		echo "\n Given String : ". $text ."\n";
		//Loop iterating string elements
		for ($i = 0; $i < $size; $i++)
		{
			//Condition which is check valid reverse k characters elements
			if ($counter == 0 && $i <= $size - $k)
			{
				$result .= $this->reverse($text, $i, $i + ($k - 1));
				$counter = $k;
				//Skip group of k-1 characters
				$i = $i + ($k - 1);
			}
			else
			{
				$counter--;
				$result .= $text[$i];
			}
		}
		echo " Alternate Characters : ". $k ."\n";
		return $result;
	}
}

function main()
{
	$obj = new MyString();
	$text = "123ABC567EFG";
	$text = $obj->reverse_alternate_char($text, 3);
	echo " After Result : ". $text ."\n";
	$text = "12345ABCDE678";
	$text = $obj->reverse_alternate_char($text, 5);
	echo " After Result : ". $text ."\n";
	$text = "1234ABCD1234ABCDEF";
	$text = $obj->reverse_alternate_char($text, 4);
	echo " After Result : ". $text ."\n";
	$text = "ABCDEFGHIJKLMO";
	$text = $obj->reverse_alternate_char($text, 2);
	echo " After Result : ". $text ."\n";
}
main();

Output

 Given String : 123ABC567EFG
 Alternate Characters : 3
 After Result : 321ABC765EFG

 Given String : 12345ABCDE678
 Alternate Characters : 5
 After Result : 54321ABCDE678

 Given String : 1234ABCD1234ABCDEF
 Alternate Characters : 4
 After Result : 4321ABCD4321ABCDEF

 Given String : ABCDEFGHIJKLMO
 Alternate Characters : 2
 After Result : BACDFEGHJIKLOM
//Node Js Program 
//Reverse alternate k characters in a string
class MyString
{
	//Reverse the substrings between given location
	//Returns reversal form of substring of given location
	reverse(text, start, end)
	{
		if (start == end)
		{
			return "";
		}
		var result = "";
		//Reverse the string element from start to end location
		for (var i = start; i <= end; i++)
		{
			result = text[i] + result;
		}
		return result;
	}
	//This function is reversing alternate groups of k characters
	reverse_alternate_char(text, k)
	{
		var size = text.length;
		if (k <= 0 || size <= 0)
		{
			return text;
		}
		//loop controlling variable [i]
		var i = 0;
		//This is store the resultant result
		var result = "";
		//This is used to detect reversal location
		var counter = 0;
		process.stdout.write("\n Given String : " + text + "\n");
		//Loop iterating string elements
		for (i = 0; i < size; i++)
		{
			//Condition which is check valid reverse k characters elements
			if (counter == 0 && i <= size - k)
			{
				result += this.reverse(text, i, i + (k - 1));
				counter = k;
				//Skip group of k-1 characters
				i = i + (k - 1);
			}
			else
			{
				counter--;
				result += text[i];
			}
		}
		process.stdout.write(" Alternate Characters : " + k + "\n");
		return result;
	}
}

function main()
{
	var obj = new MyString();
	var text = "123ABC567EFG";
	text = obj.reverse_alternate_char(text, 3);
	process.stdout.write(" After Result : " + text + "\n");
	text = "12345ABCDE678";
	text = obj.reverse_alternate_char(text, 5);
	process.stdout.write(" After Result : " + text + "\n");
	text = "1234ABCD1234ABCDEF";
	text = obj.reverse_alternate_char(text, 4);
	process.stdout.write(" After Result : " + text + "\n");
	text = "ABCDEFGHIJKLMO";
	text = obj.reverse_alternate_char(text, 2);
	process.stdout.write(" After Result : " + text + "\n");
}
main();

Output

 Given String : 123ABC567EFG
 Alternate Characters : 3
 After Result : 321ABC765EFG

 Given String : 12345ABCDE678
 Alternate Characters : 5
 After Result : 54321ABCDE678

 Given String : 1234ABCD1234ABCDEF
 Alternate Characters : 4
 After Result : 4321ABCD4321ABCDEF

 Given String : ABCDEFGHIJKLMO
 Alternate Characters : 2
 After Result : BACDFEGHJIKLOM
# Python 3 Program 
# Reverse alternate k characters in a string
class MyString :
	# Reverse the substrings between given location
	# Returns reversal form of substring of given location
	def reverse(self, text, start, end) :
		if (start == end) :
			return ""
		
		result = ""
		# Reverse the string element from start to end location
		i = start
		while (i <= end) :
			result = text[i] + result
			i += 1
		
		return result
	
	# This function is reversing alternate groups of k characters
	def reverse_alternate_char(self, text, k) :
		size = len(text)
		if (k <= 0 or size <= 0) :
			return text
		
		# loop controlling variable [i]
		i = 0
		# This is store the resultant result
		result = ""
		# This is used to detect reversal location
		counter = 0
		print("\n Given String : ", text )
		# Loop iterating string elements
		while (i < size) :
			# Condition which is check valid reverse k characters elements
			if (counter == 0 and i <= size - k) :
				result += self.reverse(text, i, i + (k - 1))
				counter = k
				# Skip group of k-1 characters
				i = i + (k - 1)
			else :
				counter -= 1
				result += text[i]
			
			i += 1
		
		print(" Alternate Characters : ", k )
		return result
	

def main() :
	obj = MyString()
	text = "123ABC567EFG"
	text = obj.reverse_alternate_char(text, 3)
	print(" After Result : ", text )
	text = "12345ABCDE678"
	text = obj.reverse_alternate_char(text, 5)
	print(" After Result : ", text )
	text = "1234ABCD1234ABCDEF"
	text = obj.reverse_alternate_char(text, 4)
	print(" After Result : ", text )
	text = "ABCDEFGHIJKLMO"
	text = obj.reverse_alternate_char(text, 2)
	print(" After Result : ", text )

if __name__ == "__main__": main()

Output

 Given String :  123ABC567EFG
 Alternate Characters :  3
 After Result :  321ABC765EFG

 Given String :  12345ABCDE678
 Alternate Characters :  5
 After Result :  54321ABCDE678

 Given String :  1234ABCD1234ABCDEF
 Alternate Characters :  4
 After Result :  4321ABCD4321ABCDEF

 Given String :  ABCDEFGHIJKLMO
 Alternate Characters :  2
 After Result :  BACDFEGHJIKLOM
# Ruby Program 
# Reverse alternate k characters in a string
class MyString

	# Reverse the substrings between given location
	# Returns reversal form of substring of given location
	def reverse(text, start, ends)
	
		if (start == ends)
		
			return ""
		end
		result = ""
		# Reverse the string element from start to end location
		i = start
		while (i <= ends)
		
			result = text[i] + result
			i += 1
		end
		return result
	end
	# This function is reversing alternate groups of k characters
	def reverse_alternate_char(text, k)
	
		size = text.length()
		if (k <= 0 || size <= 0)
		
			return text
		end
		# loop controlling variable [i]
		i = 0
		# This is store the resultant result
		result = ""
		# This is used to detect reversal location
		counter = 0
		print("\n Given String : ", text ,"\n")
		# Loop iterating string elements
		while (i < size)
		
			# Condition which is check valid reverse k characters elements
			if (counter == 0 && i <= size - k)
			
				result += self.reverse(text, i, i + (k - 1))
				counter = k
				# Skip group of k-1 characters
				i = i + (k - 1)
			else
			
				counter -= 1
				result += text[i]
			end
			i += 1
		end
		print(" Alternate Characters : ", k ,"\n")
		return result
	end
end
def main()

	obj = MyString.new()
	text = "123ABC567EFG"
	text = obj.reverse_alternate_char(text, 3)
	print(" After Result : ", text ,"\n")
	text = "12345ABCDE678"
	text = obj.reverse_alternate_char(text, 5)
	print(" After Result : ", text ,"\n")
	text = "1234ABCD1234ABCDEF"
	text = obj.reverse_alternate_char(text, 4)
	print(" After Result : ", text ,"\n")
	text = "ABCDEFGHIJKLMO"
	text = obj.reverse_alternate_char(text, 2)
	print(" After Result : ", text ,"\n")
end
main()

Output

 Given String : 123ABC567EFG
 Alternate Characters : 3
 After Result : 321ABC765EFG

 Given String : 12345ABCDE678
 Alternate Characters : 5
 After Result : 54321ABCDE678

 Given String : 1234ABCD1234ABCDEF
 Alternate Characters : 4
 After Result : 4321ABCD4321ABCDEF

 Given String : ABCDEFGHIJKLMO
 Alternate Characters : 2
 After Result : BACDFEGHJIKLOM

//Scala Program 
//Reverse alternate k characters in a string
class MyString
{
	//Reverse the substrings between given location
	//Returns reversal form of substring of given location
	def reverse(text: String, start: Int, end: Int): String = {
		if (start == end)
		{
			return "";
		}
		var result: String = "";
		//Reverse the string element from start to end location
		var i: Int = start;
		while (i <= end)
		{
			result = ""+ text(i) + result;
			i += 1;
		}
		return result;
	}
	//This function is reversing alternate groups of k characters
	def reverse_alternate_char(text: String, k: Int): String = {
		var size: Int = text.length();
		if (k <= 0 || size <= 0)
		{
			return text;
		}
		//loop controlling variable [i]
		var i: Int = 0;
		//This is store the resultant result
		var result: String = "";
		//This is used to detect reversal location
		var counter: Int = 0;
		print("\n Given String : " + text + "\n");
		//Loop iterating string elements
		while (i < size)
		{
			//Condition which is check valid reverse k characters elements
			if (counter == 0 && i <= size - k)
			{
				result += reverse(text, i, i + (k - 1));
				counter = k;
				//Skip group of k-1 characters
				i = i + (k - 1);
			}
			else
			{
				counter -= 1;
				result += text(i);
			}
			i += 1;
		}
		print(" Alternate Characters : " + k + "\n");
		return result;
	}
}
object Main
{
	def main(args: Array[String]): Unit = {
		var obj: MyString = new MyString();
		var text: String = "123ABC567EFG";
		text = obj.reverse_alternate_char(text, 3);
		print(" After Result : " + text + "\n");
		text = "12345ABCDE678";
		text = obj.reverse_alternate_char(text, 5);
		print(" After Result : " + text + "\n");
		text = "1234ABCD1234ABCDEF";
		text = obj.reverse_alternate_char(text, 4);
		print(" After Result : " + text + "\n");
		text = "ABCDEFGHIJKLMO";
		text = obj.reverse_alternate_char(text, 2);
		print(" After Result : " + text + "\n");
	}
}

Output

 Given String : 123ABC567EFG
 Alternate Characters : 3
 After Result : 321ABC765EFG

 Given String : 12345ABCDE678
 Alternate Characters : 5
 After Result : 54321ABCDE678

 Given String : 1234ABCD1234ABCDEF
 Alternate Characters : 4
 After Result : 4321ABCD4321ABCDEF

 Given String : ABCDEFGHIJKLMO
 Alternate Characters : 2
 After Result : BACDFEGHJIKLOM
//Swift Program 
//Reverse alternate k characters in a string
class MyString
{
	//Reverse the substrings between given location
	//Returns reversal form of substring of given location
	func reverse(_ data: String, _ start: Int, _ end: Int) -> String
	{
      	var text = Array(data);
      
		if (start == end)
		{
			return "";
		}
		var result: String = "";
		//Reverse the string element from start to end location
		var i: Int = start;
		while (i <= end)
		{
			result = String(text[i]) + result;
			i += 1;
		}
		return result;
	}
	//This function is reversing alternate groups of k characters
	func reverse_alternate_char(_ data: String, _ k: Int) -> String
	{
		let size: Int = data.count;
      	let text = Array(data);
		if (k <= 0 || size <= 0)
		{
			return data;
		}
		//loop controlling variable [i]
		var i: Int = 0;
		//This is store the resultant result
		var result: String = "";
		//This is used to detect reversal location
		var counter: Int = 0;
		print("\n Given String : ", data );
		//Loop iterating string elements
		while (i < size)
		{
			//Condition which is check valid reverse k characters elements
			if (counter == 0 && i <= size - k)
			{
				result += self.reverse(data, i, i + (k - 1));
				counter = k;
				//Skip group of k-1 characters
				i = i + (k - 1);
			}
			else
			{
				counter -= 1;
				result += String(text[i]);
			}
			i += 1;
		}
		print(" Alternate Characters : ", k );
		return result;
	}
}
func main()
{
	let obj: MyString = MyString();
	var text: String = "123ABC567EFG";
	text = obj.reverse_alternate_char(text, 3);
	print(" After Result : ", text );
	text = "12345ABCDE678";
	text = obj.reverse_alternate_char(text, 5);
	print(" After Result : ", text );
	text = "1234ABCD1234ABCDEF";
	text = obj.reverse_alternate_char(text, 4);
	print(" After Result : ", text );
	text = "ABCDEFGHIJKLMO";
	text = obj.reverse_alternate_char(text, 2);
	print(" After Result : ", text );
}
main();

Output

 Given String :  123ABC567EFG
 Alternate Characters :  3
 After Result :  321ABC765EFG

 Given String :  12345ABCDE678
 Alternate Characters :  5
 After Result :  54321ABCDE678

 Given String :  1234ABCD1234ABCDEF
 Alternate Characters :  4
 After Result :  4321ABCD4321ABCDEF

 Given String :  ABCDEFGHIJKLMO
 Alternate Characters :  2
 After Result :  BACDFEGHJIKLOM
Last updated on by Kalkicode




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