[Programmers] 문자열 내 p와 y의 개수 (Java)

https://programmers.co.kr/learn/courses/30/lessons/12916

charAt()

public char charAt​(int index)

Returns the char value at the specified index.
An index ranges from 0 to length() - 1.
The first char value of the sequence is at index 0, the next at index 1, and so on, as for array indexing.
If the char value specified by the index is a surrogate, the surrogate value is returned.

Specified by:
charAt in interface CharSequence
Parameters:
index - the index of the char value.
Returns:
the char value at the specified index of this string. The first char value is at index 0.
Throws:
IndexOutOfBoundsException - if the index argument is negative or not less than the length of this string.

Source

Solution

class Solution {
    static boolean solution(String s) {
        boolean answer = true;

        String lowerStr = s.toLowerCase();

        int countP = 0;
        int countY = 0;

        for (int i = 0; i < lowerStr.length(); i++) {
            if (lowerStr.charAt(i) == 'p') {
                countP++;
            } else if (lowerStr.charAt(i) == 'y') {
                countY++;
            }
        }

        if (countP != countY) { // only if count is different -> return true
            answer = false;
        }

        return answer;
    }

    public static void main(String[] args) {
        System.out.println(solution("pPoooyY"));
        System.out.println(solution("Pyy"));
    }
}

Another Solution

class Solution {
    boolean solution(String s) {
        s = s.toLowerCase();
        int count = 0;

        for (int i = 0; i < s.length(); i++) {

            if (s.charAt(i) == 'p')
                count++;
            else if (s.charAt(i) == 'y')
                count--;
        }

        if (count == 0)
            return true;
        else
            return false;
    }
}