LeetCode-1021 Remove Outermost Parentheses Solution(with Java)

1. Description:

Notes:

2. Examples:

3.Solutions: 

/**
 * Created by sheepcore on 2018-12-24
 */
class Solution {
       public String removeOuterParentheses(String S) {
        StringBuilder s = new StringBuilder();
        int opened = 0;
        for (char c : S.toCharArray()) {
            if (c == '(' && opened++ > 0) s.append(c);
            if (c == ')' && opened-- > 1) s.append(c);
        }
        return s.toString();
    }
}