Remove all adjacent duplicate characters using recursion
The problem is to remove all adjacent duplicate characters from a given string using recursion. An adjacent duplicate character is a character that appears consecutively more than once in the string. The task is to remove such adjacent duplicates and return the modified string.
Explanation using Example
Let's consider the test cases from the provided code:
-
Test Case 1: Given Text = "apple" After removing adjacent duplicate characters, the modified string is "ale".
-
Test Case 2: Given Text = "xxyyyyx" After removing adjacent duplicate characters, the modified string is "x".
-
Test Case 3: Given Text = "xxyyyxx" After removing adjacent duplicate characters, the modified string is an empty string ("").
-
Test Case 4: Given Text = "xyyxxyx" After removing adjacent duplicate characters, the modified string is "xyx".
-
Test Case 5: Given Text = "xxxxyyyzyyzzxxx" After removing adjacent duplicate characters, the modified string is "z".
-
Test Case 6: Given Text = "xyzzyxy" After removing adjacent duplicate characters, the modified string is "y".
-
Test Case 7: Given Text = "xyxxyx" After removing adjacent duplicate characters, the modified string is an empty string ("").
Pseudocode
removeAdjacentDuplicate(text)
if text length is 0
return text
size = text length - 1
auxiliary = size
result = ""
task = false
while size >= 0
while size >= 0 and text[auxiliary] == text[size]
size--
if size + 1 == auxiliary
result = text[auxiliary] + result
else
task = true
auxiliary = size
if task
return removeAdjacentDuplicate(result)
return result
removeAdjacent(text)
print "Given Text : text"
print "Output : removeAdjacentDuplicate(text)"
Algorithm Explanation
The removeAdjacentDuplicate
function is a recursive algorithm to remove all adjacent duplicate
characters from the given text using the following steps:
- If the length of the
text
is 0, it means there are no more characters to process, and the function returns thetext
as it is. - The algorithm uses two pointers,
size
andauxiliary
, both initialized to the last index of thetext
. - The algorithm defines an empty string
result
to store the modified text without adjacent duplicates and a boolean variabletask
to indicate whether any adjacent duplicates have been removed. - The algorithm enters a loop that iterates until
size
becomes less than 0. - Inside the loop, the algorithm checks if the character at index
auxiliary
is equal to the character at indexsize
. If they are the same, it means adjacent duplicates are found, and thesize
pointer moves back to the previous character. - If
size + 1
is equal toauxiliary
, it means no adjacent duplicates were found, and the character at indexauxiliary
is added to the beginning of theresult
string. - If adjacent duplicates were found, the
task
variable is set to true to indicate that thetext
is modified. - The
auxiliary
pointer is updated to the currentsize
. - After the loop, the algorithm checks if any modifications were made (
task == true
). If so, it recursively calls itself with theresult
as the newtext
. - If no modifications were made, the algorithm returns the
result
.
The removeAdjacent
function handles the request to remove adjacent duplicates from the given text. It
first prints the given text and then prints the modified text obtained from the removeAdjacentDuplicate
function.
Code Solution
Here given code implementation process.
/*
Java Program for
Remove all adjacent duplicate characters using recursion
*/
public class RemoveCharacters
{
// Recursively, removing the all adjacent similar characters
public String removeAdjacentDuplicate(String text)
{
if (text.length() == 0)
{
return text;
}
// Define some auxiliary variable
int size = text.length() - 1;
int auxiliary = size;
String result = "";
boolean task = false;
// Execute loop until when size is less than zero
while (size >= 0)
{
// Skip similar adjacent characters
while (size >= 0 && text.charAt(auxiliary) == text.charAt(size))
{
size--;
}
if (size + 1 == auxiliary)
{
// When adjacent are not same
// Then add new character at beginning of result
result = text.charAt(auxiliary) + result;
}
else
{
// This is indicate string is modified
task = true;
}
// Get new index
auxiliary = size;
}
if (task)
{
return removeAdjacentDuplicate(result);
}
return result;
}
// Handles the request to printing calculate result
public void removeAdjacent(String text)
{
System.out.println(" Given Text : " + text);
System.out.println(" Output : " + removeAdjacentDuplicate(text));
}
public static void main(String[] args)
{
RemoveCharacters test = new RemoveCharacters();
// Test Cases
test.removeAdjacent("apple");
test.removeAdjacent("xxyyyyx");
test.removeAdjacent("xxyyyxx");
test.removeAdjacent("xyyxxyx");
test.removeAdjacent("xxxxyyyzyyzzxxx");
test.removeAdjacent("xyzzyxy");
test.removeAdjacent("xyxxyx");
}
}
input
Given Text : apple
Output : ale
Given Text : xxyyyyx
Output : x
Given Text : xxyyyxx
Output :
Given Text : xyyxxyx
Output : xyx
Given Text : xxxxyyyzyyzzxxx
Output : z
Given Text : xyzzyxy
Output : y
Given Text : xyxxyx
Output :
// Include header file
#include <iostream>
#include <string>
using namespace std;
/*
C++ Program for
Remove all adjacent duplicate characters using recursion
*/
class RemoveCharacters
{
public:
// Recursively, removing the all adjacent similar characters
string removeAdjacentDuplicate(string text)
{
if (text.length() == 0)
{
return text;
}
// Define some auxiliary variable
int size = text.length() - 1;
int auxiliary = size;
string result = "";
bool task = false;
// Execute loop until when size is less than zero
while (size >= 0)
{
// Skip similar adjacent characters
while (size >= 0 && text[auxiliary] == text[size])
{
size--;
}
if (size + 1 == auxiliary)
{
// When adjacent are not same
// Then add new character at beginning of result
result = text[auxiliary] + result;
}
else
{
// This is indicate string is modified
task = true;
}
// Get new index
auxiliary = size;
}
if (task)
{
return this->removeAdjacentDuplicate(result);
}
return result;
}
// Handles the request to printing calculate result
void removeAdjacent(string text)
{
cout << " Given Text : " << text << endl;
cout << " Output : " << this->removeAdjacentDuplicate(text) << endl;
}
};
int main()
{
RemoveCharacters *test = new RemoveCharacters();
// Test Cases
test->removeAdjacent("apple");
test->removeAdjacent("xxyyyyx");
test->removeAdjacent("xxyyyxx");
test->removeAdjacent("xyyxxyx");
test->removeAdjacent("xxxxyyyzyyzzxxx");
test->removeAdjacent("xyzzyxy");
test->removeAdjacent("xyxxyx");
return 0;
}
input
Given Text : apple
Output : ale
Given Text : xxyyyyx
Output : x
Given Text : xxyyyxx
Output :
Given Text : xyyxxyx
Output : xyx
Given Text : xxxxyyyzyyzzxxx
Output : z
Given Text : xyzzyxy
Output : y
Given Text : xyxxyx
Output :
// Include namespace system
using System;
/*
Csharp Program for
Remove all adjacent duplicate characters using recursion
*/
public class RemoveCharacters
{
// Recursively, removing the all adjacent similar characters
public String removeAdjacentDuplicate(String text)
{
if (text.Length == 0)
{
return text;
}
// Define some auxiliary variable
int size = text.Length - 1;
int auxiliary = size;
String result = "";
Boolean task = false;
// Execute loop until when size is less than zero
while (size >= 0)
{
// Skip similar adjacent characters
while (size >= 0 && text[auxiliary] == text[size])
{
size--;
}
if (size + 1 == auxiliary)
{
// When adjacent are not same
// Then add new character at beginning of result
result = text[auxiliary] + result;
}
else
{
// This is indicate string is modified
task = true;
}
// Get new index
auxiliary = size;
}
if (task)
{
return this.removeAdjacentDuplicate(result);
}
return result;
}
// Handles the request to printing calculate result
public void removeAdjacent(String text)
{
Console.WriteLine(" Given Text : " + text);
Console.WriteLine(" Output : " + this.removeAdjacentDuplicate(text));
}
public static void Main(String[] args)
{
RemoveCharacters test = new RemoveCharacters();
// Test Cases
test.removeAdjacent("apple");
test.removeAdjacent("xxyyyyx");
test.removeAdjacent("xxyyyxx");
test.removeAdjacent("xyyxxyx");
test.removeAdjacent("xxxxyyyzyyzzxxx");
test.removeAdjacent("xyzzyxy");
test.removeAdjacent("xyxxyx");
}
}
input
Given Text : apple
Output : ale
Given Text : xxyyyyx
Output : x
Given Text : xxyyyxx
Output :
Given Text : xyyxxyx
Output : xyx
Given Text : xxxxyyyzyyzzxxx
Output : z
Given Text : xyzzyxy
Output : y
Given Text : xyxxyx
Output :
<?php
/*
Php Program for
Remove all adjacent duplicate characters using recursion
*/
class RemoveCharacters
{
// Recursively, removing the all adjacent similar characters
public function removeAdjacentDuplicate($text)
{
if (strlen($text) == 0)
{
return $text;
}
// Define some auxiliary variable
$size = strlen($text) - 1;
$auxiliary = $size;
$result = "";
$task = false;
// Execute loop until when size is less than zero
while ($size >= 0)
{
// Skip similar adjacent characters
while ($size >= 0 && $text[$auxiliary] == $text[$size])
{
$size--;
}
if ($size + 1 == $auxiliary)
{
// When adjacent are not same
// Then add new character at beginning of result
$result = $text[$auxiliary].$result;
}
else
{
// This is indicate string is modified
$task = true;
}
// Get new index
$auxiliary = $size;
}
if ($task)
{
return $this->removeAdjacentDuplicate($result);
}
return $result;
}
// Handles the request to printing calculate result
public function removeAdjacent($text)
{
echo " Given Text : ".$text.
"\n";
echo " Output : ".$this->removeAdjacentDuplicate($text).
"\n";
}
}
function main()
{
$test = new RemoveCharacters();
// Test Cases
$test->removeAdjacent("apple");
$test->removeAdjacent("xxyyyyx");
$test->removeAdjacent("xxyyyxx");
$test->removeAdjacent("xyyxxyx");
$test->removeAdjacent("xxxxyyyzyyzzxxx");
$test->removeAdjacent("xyzzyxy");
$test->removeAdjacent("xyxxyx");
}
main();
input
Given Text : apple
Output : ale
Given Text : xxyyyyx
Output : x
Given Text : xxyyyxx
Output :
Given Text : xyyxxyx
Output : xyx
Given Text : xxxxyyyzyyzzxxx
Output : z
Given Text : xyzzyxy
Output : y
Given Text : xyxxyx
Output :
/*
Node JS Program for
Remove all adjacent duplicate characters using recursion
*/
class RemoveCharacters
{
// Recursively, removing the all adjacent similar characters
removeAdjacentDuplicate(text)
{
if (text.length == 0)
{
return text;
}
// Define some auxiliary variable
var size = text.length - 1;
var auxiliary = size;
var result = "";
var task = false;
// Execute loop until when size is less than zero
while (size >= 0)
{
// Skip similar adjacent characters
while (size >= 0 && text.charAt(auxiliary) == text.charAt(size))
{
size--;
}
if (size + 1 == auxiliary)
{
// When adjacent are not same
// Then add new character at beginning of result
result = text.charAt(auxiliary) + result;
}
else
{
// This is indicate string is modified
task = true;
}
// Get new index
auxiliary = size;
}
if (task)
{
return this.removeAdjacentDuplicate(result);
}
return result;
}
// Handles the request to printing calculate result
removeAdjacent(text)
{
console.log(" Given Text : " + text);
console.log(" Output : " + this.removeAdjacentDuplicate(text));
}
}
function main()
{
var test = new RemoveCharacters();
// Test Cases
test.removeAdjacent("apple");
test.removeAdjacent("xxyyyyx");
test.removeAdjacent("xxyyyxx");
test.removeAdjacent("xyyxxyx");
test.removeAdjacent("xxxxyyyzyyzzxxx");
test.removeAdjacent("xyzzyxy");
test.removeAdjacent("xyxxyx");
}
main();
input
Given Text : apple
Output : ale
Given Text : xxyyyyx
Output : x
Given Text : xxyyyxx
Output :
Given Text : xyyxxyx
Output : xyx
Given Text : xxxxyyyzyyzzxxx
Output : z
Given Text : xyzzyxy
Output : y
Given Text : xyxxyx
Output :
# Python 3 Program for
# Remove all adjacent duplicate characters using recursion
class RemoveCharacters :
# Recursively, removing the all adjacent similar characters
def removeAdjacentDuplicate(self, text) :
if (len(text) == 0) :
return text
size = len(text) - 1
auxiliary = size
result = ""
task = False
# Execute loop until when size is less than zero
while (size >= 0) :
# Skip similar adjacent characters
while (size >= 0 and text[auxiliary] == text[size]) :
size -= 1
if (size + 1 == auxiliary) :
# When adjacent are not same
# Then add new character at beginning of result
result = text[auxiliary] + result
else :
# This is indicate string is modified
task = True
# Get new index
auxiliary = size
if (task) :
return self.removeAdjacentDuplicate(result)
return result
# Handles the request to printing calculate result
def removeAdjacent(self, text) :
print(" Given Text : ", text)
print(" Output : ", self.removeAdjacentDuplicate(text))
def main() :
test = RemoveCharacters()
# Test Cases
test.removeAdjacent("apple")
test.removeAdjacent("xxyyyyx")
test.removeAdjacent("xxyyyxx")
test.removeAdjacent("xyyxxyx")
test.removeAdjacent("xxxxyyyzyyzzxxx")
test.removeAdjacent("xyzzyxy")
test.removeAdjacent("xyxxyx")
if __name__ == "__main__": main()
input
Given Text : apple
Output : ale
Given Text : xxyyyyx
Output : x
Given Text : xxyyyxx
Output :
Given Text : xyyxxyx
Output : xyx
Given Text : xxxxyyyzyyzzxxx
Output : z
Given Text : xyzzyxy
Output : y
Given Text : xyxxyx
Output :
# Ruby Program for
# Remove all adjacent duplicate characters using recursion
class RemoveCharacters
# Recursively, removing the all adjacent similar characters
def removeAdjacentDuplicate(text)
if (text.length == 0)
return text
end
# Define some auxiliary variable
size = text.length - 1
auxiliary = size
result = ""
task = false
# Execute loop until when size is less than zero
while (size >= 0)
# Skip similar adjacent characters
while (size >= 0 && text[auxiliary] == text[size])
size -= 1
end
if (size + 1 == auxiliary)
# When adjacent are not same
# Then add new character at beginning of result
result = text[auxiliary] + result
else
# This is indicate string is modified
task = true
end
# Get new index
auxiliary = size
end
if (task)
return self.removeAdjacentDuplicate(result)
end
return result
end
# Handles the request to printing calculate result
def removeAdjacent(text)
print(" Given Text : ", text, "\n")
print(" Output : ", self.removeAdjacentDuplicate(text), "\n")
end
end
def main()
test = RemoveCharacters.new()
# Test Cases
test.removeAdjacent("apple")
test.removeAdjacent("xxyyyyx")
test.removeAdjacent("xxyyyxx")
test.removeAdjacent("xyyxxyx")
test.removeAdjacent("xxxxyyyzyyzzxxx")
test.removeAdjacent("xyzzyxy")
test.removeAdjacent("xyxxyx")
end
main()
input
Given Text : apple
Output : ale
Given Text : xxyyyyx
Output : x
Given Text : xxyyyxx
Output :
Given Text : xyyxxyx
Output : xyx
Given Text : xxxxyyyzyyzzxxx
Output : z
Given Text : xyzzyxy
Output : y
Given Text : xyxxyx
Output :
/*
Scala Program for
Remove all adjacent duplicate characters using recursion
*/
class RemoveCharacters()
{
// Recursively, removing the all adjacent similar characters
def removeAdjacentDuplicate(text: String): String = {
if (text.length() == 0)
{
return text;
}
// Define some auxiliary variable
var size: Int = text.length() - 1;
var auxiliary: Int = size;
var result: String = "";
var task: Boolean = false;
// Execute loop until when size is less than zero
while (size >= 0)
{
// Skip similar adjacent characters
while (size >= 0 && text.charAt(auxiliary) == text.charAt(size))
{
size -= 1;
}
if (size + 1 == auxiliary)
{
// When adjacent are not same
// Then add new character at beginning of result
result = ""+ text.charAt(auxiliary) + result;
}
else
{
// This is indicate string is modified
task = true;
}
// Get new index
auxiliary = size;
}
if (task)
{
return removeAdjacentDuplicate(result);
}
return result;
}
// Handles the request to printing calculate result
def removeAdjacent(text: String): Unit = {
println(" Given Text : " + text);
println(" Output : " + removeAdjacentDuplicate(text));
}
}
object Main
{
def main(args: Array[String]): Unit = {
var test: RemoveCharacters = new RemoveCharacters();
// Test Cases
test.removeAdjacent("apple");
test.removeAdjacent("xxyyyyx");
test.removeAdjacent("xxyyyxx");
test.removeAdjacent("xyyxxyx");
test.removeAdjacent("xxxxyyyzyyzzxxx");
test.removeAdjacent("xyzzyxy");
test.removeAdjacent("xyxxyx");
}
}
input
Given Text : apple
Output : ale
Given Text : xxyyyyx
Output : x
Given Text : xxyyyxx
Output :
Given Text : xyyxxyx
Output : xyx
Given Text : xxxxyyyzyyzzxxx
Output : z
Given Text : xyzzyxy
Output : y
Given Text : xyxxyx
Output :
/*
Swift 4 Program for
Remove all adjacent duplicate characters using recursion
*/
class RemoveCharacters
{
// Recursively, removing the all adjacent similar characters
func removeAdjacentDuplicate(_ t: String)->String
{
let text = Array(t);
if (text.count == 0)
{
return t;
}
// Define some auxiliary variable
var size: Int = text.count - 1;
var auxiliary: Int = size;
var result: String = "";
var task: Bool = false;
// Execute loop until when size is less than zero
while (size >= 0)
{
// Skip similar adjacent characters
while (size >= 0 && text[auxiliary] == text[size])
{
size -= 1;
}
if (size + 1 == auxiliary)
{
// When adjacent are not same
// Then add new character at beginning of result
result = String(text[auxiliary]) + result;
}
else
{
// This is indicate string is modified
task = true;
}
// Get new index
auxiliary = size;
}
if (task)
{
return self.removeAdjacentDuplicate(result);
}
return result;
}
// Handles the request to printing calculate result
func removeAdjacent(_ text: String)
{
print(" Given Text : ", text);
print(" Output : ", self.removeAdjacentDuplicate(text));
}
}
func main()
{
let test: RemoveCharacters = RemoveCharacters();
// Test Cases
test.removeAdjacent("apple");
test.removeAdjacent("xxyyyyx");
test.removeAdjacent("xxyyyxx");
test.removeAdjacent("xyyxxyx");
test.removeAdjacent("xxxxyyyzyyzzxxx");
test.removeAdjacent("xyzzyxy");
test.removeAdjacent("xyxxyx");
}
main();
input
Given Text : apple
Output : ale
Given Text : xxyyyyx
Output : x
Given Text : xxyyyxx
Output :
Given Text : xyyxxyx
Output : xyx
Given Text : xxxxyyyzyyzzxxx
Output : z
Given Text : xyzzyxy
Output : y
Given Text : xyxxyx
Output :
/*
Kotlin Program for
Remove all adjacent duplicate characters using recursion
*/
class RemoveCharacters
{
// Recursively, removing the all adjacent similar characters
fun removeAdjacentDuplicate(text: String): String ?
{
if (text.length == 0)
{
return text;
}
// Define some auxiliary variable
var size: Int = text.length - 1;
var auxiliary: Int = size;
var result: String = "";
var task: Boolean = false;
while (size >= 0)
{
while (size >= 0 && text.get(auxiliary) == text.get(size))
{
size -= 1;
}
if (size + 1 == auxiliary)
{
// When adjacent are not same
// Then add new character at beginning of result
result = text.get(auxiliary) + result;
}
else
{
// This is indicate string is modified
task = true;
}
// Get new index
auxiliary = size;
}
if (task)
{
return this.removeAdjacentDuplicate(result);
}
return result;
}
// Handles the request to printing calculate result
fun removeAdjacent(text: String): Unit
{
println(" Given Text : " + text);
println(" Output : " + this.removeAdjacentDuplicate(text));
}
}
fun main(args: Array < String > ): Unit
{
val test: RemoveCharacters = RemoveCharacters();
// Test Cases
test.removeAdjacent("apple");
test.removeAdjacent("xxyyyyx");
test.removeAdjacent("xxyyyxx");
test.removeAdjacent("xyyxxyx");
test.removeAdjacent("xxxxyyyzyyzzxxx");
test.removeAdjacent("xyzzyxy");
test.removeAdjacent("xyxxyx");
}
input
Given Text : apple
Output : ale
Given Text : xxyyyyx
Output : x
Given Text : xxyyyxx
Output :
Given Text : xyyxxyx
Output : xyx
Given Text : xxxxyyyzyyzzxxx
Output : z
Given Text : xyzzyxy
Output : y
Given Text : xyxxyx
Output :
Time Complexity
The time complexity of the provided algorithm depends on the length of the input text
. The algorithm
performs a linear scan through the characters of the text
in the worst case. Therefore, the time
complexity is O(n)
, where n
is the length of the text
.
Resultant Output Explanation
The code correctly removes all adjacent duplicate characters using recursion for the given test cases:
- For
text = "apple"
, the modified text is "ale". - For
text = "xxyyyyx"
, the modified text is "x". - For
text = "xxyyyxx"
, the modified text is an empty string (""). - For
text = "xyyxxyx"
, the modified text is "xyx". - For
text = "xxxxyyyzyyzzxxx"
, the modified text is "z". - For
text = "xyzzyxy"
, the modified text is "y". - For
text = "xyxxyx"
, the modified text is an empty string ("").
The algorithm efficiently removes all adjacent duplicate characters from the given text using recursion and provides the correct modified text for the provided test cases.
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