Compare Strings

public class Solution {
    /**
     * @param A : A string includes Upper Case letters
     * @param B : A string includes Upper Case letter
     * @return :  if string A contains all of the characters in B return true else return false
     */
    public boolean compareStrings(String A, String B) {
        // write your code here
        if (A.length() < B.length()){
            return false;
        }
        char[] charA = A.toCharArray();
        char[] charB = B.toCharArray();
        int[] nums = new int[27];
        int index;
        for (int i = 0; i < A.length(); i++){
            index = charA[i] - 'A';
            nums[index]++;
        }
        for (int j = 0; j < B.length(); j++){
            index = charB[j] - 'A';
            nums[index]--;
            if (nums[index] < 0){
                return false;
            }
        }
        return true;
    }
}