You are given an array of strings  and a string .

A string is good if it can be formed by characters from chars (each character can only be used once).

Return the sum of lengths of all good strings in words.

Example 1:

Input: words = ["cat&#​34;,"bt&#​34;,"hat&#​34;,"tree&#​34;], chars = "atach&#​34;Output: 6Explanation: The strings that can be formed are "cat&#​34; and "hat&#​34; so the answer is 3 + 3 = 6.

Example 2:

Input: words = ["hello&#​34;,"world&#​34;,"leetcode&#​34;], chars = "welldonehoneyr&#​34;Output: 10Explanation: The strings that can be formed are "hello&#​34; and "world&#​34; so the answer is 5 + 5 = 10.

Constraints:

• 1 <= words.length <= 1000

• 1 <= words[i].length, chars.length <= 100

• words[i] and chars consist of lowercase English letters.

class Solution {
    public int countCharacters(String[] words, String chars) {
         int [] freq = new int [26];
        for(int i=0;i<chars.length();i++)
            freq[chars.charAt(i)-'a']++;
        
        int sum=0;
        for(String word: words){
            int[] check = Arrays.copyOf(freq,freq.length);
            boolean valid = true;

            for(int i=0;i<word.length();i++){
                if(-- check[word.charAt(i)-'a']<0){
                    valid=false;
                    break;
                }
            }
            if(valid) sum+=word.length();
        }
  
        
        
        return sum;
    }
}

Runtime: 4 ms, faster than 98.54% of Java online submissions for Find Words That Can Be Formed by Characters.

Memory Usage: 42.6 MB, less than 91.35% of Java online submissions for Find Words That Can Be Formed by Characters.