alternating-characters.java

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;

public class Solution {

    // Complete the alternatingCharacters function below.
    static int alternatingCharacters(String s) {
        char previousCharacter = s.charAt(0);

        int count = 0;
        for (int i = 1; i < s.length(); i++) {
            if (previousCharacter == s.charAt(i)) {
                count++;
            } else {
                previousCharacter = s.charAt(i);
            }
        }

        return count;
    }

    private static final Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) throws IOException {
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        int q = scanner.nextInt();
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        for (int qItr = 0; qItr < q; qItr++) {
            String s = scanner.nextLine();

            int result = alternatingCharacters(s);

            bufferedWriter.write(String.valueOf(result));
            bufferedWriter.newLine();
        }

        bufferedWriter.close();

        scanner.close();
    }
}