Sponsored
Sponsored
Utilize a stack to handle the nested or paired parentheses efficiently. By pushing characters onto a stack until a closing parenthesis is encountered, then reversing the needed substring, you can leverage the stack's LIFO properties to achieve the desired result.
Time Complexity: O(n).
Space Complexity: O(n) due to the stack usage for storing characters.
1def reverseParentheses(s):
2 stack = []
3 for char in s:
4 if char == ')':
5 queue = []
6 while stack and stack[-1] != '(':
7 queue.append(stack.pop())
8 stack.pop() # pop '('
9 stack.extend(queue)
10 else:
11 stack.append(char)
12 return ''.join(stack)
13
14
15s = '(u(love)i)'
16print(reverseParentheses(s))
17This Python implementation uses a list as a stack to reverse parts of the string contained between parentheses. By popping off characters and utilizing a temporary storage list, it reverses the sequence efficiently and appends it back onto the original processing stack.
This approach involves separately building the result string in a single pass using an auxiliary data structure to track position swaps. The use of local in-string reversals enables an efficient and clean traversal building mechanism.
Time Complexity: O(n).
Space Complexity: O(n), using additional space for parentheses pair tracking and intermediate char arrays.
The Python variant applies indexed pair storage to identify parentheses boundaries for the two-pass construction. It offers a clean mechanism to trace and modify the sequence of characters accordingly, ensuring an efficient parsing and building process.