Number of Changing Keys

You are given a 0-indexed string s typed by a user. Changing a key is defined as using a key different from the last used key. For example, s = "ab" has a change of a key while s = "bBBb" does not have any.

Return the number of times the user had to change the key.

Note: Modifiers like shift or caps lock won't be counted in changing the key that is if a user typed the letter 'a' and then the letter 'A' then it will not be considered as a changing of key.

LeetCode Problem - 3019: Link | Click Here

class Solution {
    // Method to count the number of key changes in a given string
    public int countKeyChanges(String s) {

        // Initialize a variable to keep track of the count of changing keys
        int countChangingKey = 0;

        // Get the lowercase of the first character to compare with subsequent characters
        char compare = Character.toLowerCase(s.charAt(0));

        // Iterate through the string starting from the second character
        for (int i = 1; i < s.length(); i++) {
            // Get the lowercase of the current character
            char currentChar = Character.toLowerCase(s.charAt(i));

            // Compare the current character with the previous one
            if (compare != currentChar) {
                // If different, update the compare variable and increment the count of changing keys
                compare = currentChar;
                countChangingKey++;
            }
        }

        // Return the count of changing keys
        return countChangingKey;
    }
}