#3499

Maximize Active Section with Trade I

Medium
StringEnumerationHash MapArray
LeetCode ↗

Approaches

Brute ForceOptimal
Complexity Comparison
Brute ForceOptimal Solution
Time
O(n²)
O(n)
Space
O(1)
O(n)
💡

Intuition

Time O(n)Space O(n)

Count segments of '1's and '0's, then calculate potential trades efficiently by considering only valid segments.

⚙️

Algorithm

3 steps
  1. 1Step 1: Split the string into segments of '1's and '0's.
  2. 2Step 2: For each block of '1's surrounded by '0's, calculate the potential increase in active sections.
  3. 3Step 3: Return the maximum active sections after considering all valid trades.
solution.py9 lines
1def maxActiveSections(s):
2    s = '1' + s + '1'
3    segments = [len(x) for x in s.split('0')]
4    max_active = segments.count(1)
5    for i in range(1, len(segments) - 1):
6        if segments[i] > 1:
7            new_active = max_active - 1 + 2
8            max_active = max(max_active, new_active)
9    return max_active

Complexity note: Linear time complexity due to single pass through the string and segments.

  • 1Identifying segments helps optimize the problem.
  • 2Surrounding conditions dictate valid trades.

Solutions and explanations are original Tejav content. Problem titles © LeetCode — use the LeetCode button above for the full problem statement.