1002. 查找常用字符

1002. 查找常用字符

class Solution {
    public List<String> commonChars(String[] A) {
        List<String> ans = new ArrayList<>();
        if (A == null || A.length == 0)
            return ans;
        int[] hash = new int[26];
        for (int i = 0; i < A[0].length(); i++) {
            ++hash[A[0].charAt(i) - 'a'];
        }
        int[] other = new int[26];
        for (int i = 1; i < A.length; i++) {
            Arrays.fill(other, 0);
            for (int j = 0; j < A[i].length(); j++) {
                ++other[A[i].charAt(j) - 'a'];
            };
            for (int index = 0; index < 26; index++) {
                hash[index] = Math.min(hash[index], other[index]);
            }
        }
        for (int i = 0; i < 26; i++) {
            while (hash[i] != 0) {
                ans.add(new String("" + (char)('a' + i)));
                --hash[i];
            }
        }
        return ans;
    }
}