A valid parentheses string is either empty "", "(" + X + ")", or X + Y, where X and Y are valid parentheses strings, and + represents string concatenation.
For example, "", "()", "(())()", and "(()(()))" are all valid parentheses strings.
A valid parentheses string s is primitive if it is nonempty, and there does not exist a way to split it into s = X + Y, with X and Y nonempty valid parentheses strings.
Given a valid parentheses string s, consider its primitive decomposition: s = P_{1} + P_{2} + ... + P_{k}, where P_{i} are primitive valid parentheses strings.
Return s after removing the outermost parentheses of every primitive string in the primitive decomposition of s.
Example 1:
Input:
s = "(()())(())"
Output:
"()()()"
Explanation:
The input string is "(()())(())", with primitive decomposition "(()())" + "(())".
After removing outer parentheses of each part, this is "()()" + "()" = "()()()".
Example 2:
Input:
s = "()()"
Output:
""
Explanation:
The input string is "()()", with primitive decomposition "()" + "()".
After removing outer parentheses of each part, this is "" + "" = "".
Your Task:
You don't need to read input or print anything. Your task is to complete the function removeOuter() which takes a string s as inputs and returns s after removing the outermost parentheses of every primitive string in the primitive decomposition of s .
Expected Time Complexity: O(n)
Expected Space Complexity: O(n)
Constraint:
1 <= s.length <= 10^{5}
s[i] is either '(' or ')'
s is a valid parentheses string.

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