06. Replace Repeating Chars

import java.util.Scanner;

public class ReplaceRepeatingChars {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String input = scanner.nextLine().trim();

        StringBuilder sb = new StringBuilder();

        if (input == null || input.length() == 0) {
            return;
        }

        char previousChar = input.charAt(0);
        sb.append(previousChar);

        for (int i = 1; i < input.length(); i++) {
            char ch = input.charAt(i);
            if (ch != previousChar) {
                sb.append(ch);
                previousChar = ch;
            }
        }

        System.out.println(sb);
    }
}