Struggling with this GFG POTD problem? Let’s break it down step by step!
👉 Problem:
Given a binary array (0s and 1s), you can flip at most one subarray (convert 0→1 and 1→0).
Find the maximum number of 1’s possible after the flip.
🧠 Key Insight
Instead of flipping directly:
Treat 0 as +1 (gain)
Treat 1 as -1 (loss)
Now the problem becomes:
👉 Find the maximum subarray sum using Kadane’s Algorithm
⚡ Approaches Covered
✔ Brute Force (for understanding)
✔ Optimal Approach (Kadane’s Algorithm) – O(n)
📊 Example
Input:
[1, 0, 0, 1, 0]
Output:
4
💻 Constraints
1 ≤ n ≤ 10⁶
O(n) solution required
🚀 Why This Problem is Important
Classic Kadane’s Algorithm variation
Frequently asked in interviews
Improves problem transformation skills
