Alternating Characters HackerRank Solution

Alternating Characters HackerRank Solution
Source : https://www.hackerrank.com/challenges/alternating-characters

You are given a string containing characters and only. Your task is to change it into a string such that there are no matching adjacent characters. To do this, you are allowed to delete zero or more characters in the string.

Your task is to find the minimum number of required deletions.

For example, given the string , remove an at positions and to make in deletions.

Function Description

Complete the alternatingCharacters function in the editor below. It must return an integer representing the minimum number of deletions to make the alternating string.

alternatingCharacters has the following parameter(s):

• s: a string

Input Format

The first line contains an integer , the number of queries.
The next lines each contain a string .

Constraints

• Each string will consist only of characters and

Output Format

For each query, print the minimum number of deletions required on a new line.

Sample Input

5
AAAA
BBBBB
ABABABAB
BABABA
AAABBB

Sample Output

34004

Explanation

The characters marked red are the ones that can be deleted so that the string doesn't have matching consecutive characters.

Source : https://www.hackerrank.com/challenges/alternating-characters

Solution

	// Karthikalapati.blogspot.com
	import java.util.Scanner;
	// Each time we have 2 consecutive characters that are the same, we can delete 1 of them
	public class Solution {
	public static void main(String[] args) {
	Scanner scan = new Scanner(System.in);
	int T = scan.nextInt();
	while (T-- > 0) {
	String str = scan.next();
	System.out.println(minimumDeletions(str));
	}
	scan.close();
	}
	private static int minimumDeletions(String str) {
	int deletions = 0;
	for (int i = 1; i < str.length(); i++) {
	if (str.charAt(i) == str.charAt(i-1)) {
	deletions++;
	}
	}
	return deletions;
	}
	}