WAP to Remove Consecutive Duplicate Characters from String

This Java program aims to remove consecutive duplicate characters from a given string. It utilizes a stack data structure to achieve this.

Remove Consecutive Duplicate Characters from String

package com.softwaretestingo.interviewprograms;
import java.util.Stack;
public class InterviewPrograms39 
{
	/*
	 * Input string : weelccoommee hhoommeee 
	 * Output string : welcome home
	 */
	public static void main(String[] args) 
	{
		String s = "weelccoommee hhoommeee";
		Stack<Character> st = new Stack<>();
		st.push(s.charAt(0));
		for (int i = 1; i<s.length(); i++ ) 
		{
			if (s.charAt(i-1) != s.charAt(i))
				st.push(s.charAt(i));
		}
		for ( Character c : st )
			System.out.print(c) ;
	}
}

Output

welcome home

Alternative 1:

This Java program aims to remove consecutive duplicate characters from a given input string using regular expressions.

package com.softwaretestingo.interviewprograms;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class InterviewPrograms39_1 
{
	/*
	 * Input string : weelccoommee hhoommeee 
	 * Output string : welcome home
	 */
	public static void main(String[] args) 
	{
		String s = " weelccoomme hhommeee " ;
		Pattern pattern = Pattern.compile("(.)\\1*");
		Matcher m= pattern.matcher ( s ) ;
		String output = "";
		while ( m.find())
		{
			output= output + m.group().charAt(0);
		}
		System.out.println ( output ) ;
	}
}

Output

welcome home