https://leetcode-cn.com/problems/remove-outermost-parentheses/
Java Solution
1 class Solution { 2 public String removeOuterParentheses(String S) { 3 char[] chars = S.toCharArray(); 4 int flag = 0; 5 StringBuilder result = new StringBuilder(); 6 7 for (char c : chars) { 8 if (c == '(') { 9 if (flag == 0) { 10 flag ++; 11 continue; 12 } 13 flag ++; 14 } else if (c == ')') { 15 flag --; 16 if (flag == 0) { 17 continue; 18 } 19 } 20 result.append(c); 21 } 22 return result.toString(); 23 } 24 }