🔢 Longest Balanced Binary Subarray Finder

A Java Swing desktop app that finds the longest contiguous subarray with an equal number of 0s and 1s.

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📖 Overview

Longest Balanced Binary Subarray Finder is a lightweight Java Swing desktop application that solves a classic array problem: given a binary array (only 0s and 1s), find the length of the longest contiguous subarray containing an equal number of 0s and 1s.

The app runs two implementations side by side so results can be cross-checked instantly:

🔁 Non-recursive	♻️ Recursive
Iterative prefix-sum approach	Recursive prefix-sum approach

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✨ Features

• 🖥️ Simple, intuitive Java Swing graphical interface
• ⌨️ Space-separated binary array input
• ⚖️ Side-by-side comparison of recursive vs. non-recursive results
• ⚠️ Clear, descriptive validation messages for invalid input
• 🧾 Clean output panel showing the parsed array and final result

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🧠 Algorithm Idea

The core trick: treat each 0 as -1 and each 1 as +1, then track running prefix sums.

When the same prefix sum appears twice, the elements between those two indices must contain an equal number of 0s and 1s. The maximum distance between two indices sharing a prefix sum gives the longest balanced subarray length.

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⏱️ Complexity

Approach	Time Complexity	Space Complexity
Non-recursive	O(n)	O(n)
Recursive	O(n)	O(n)

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📁 Project Structure

.
├── src/
│   ├── LongestBalancedSubarray.java
│   └── LongestBalancedSubarrayGUI.java
├── screenshots/
└── README.md

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🚀 Run Locally

1. Compile the project

javac src/*.java

2. Run the GUI

java -cp src LongestBalancedSubarrayGUI

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🧪 Example Inputs

0 1
0 1 0
0 0 1 0 1 1 0
0 0 0 0

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🖼️ Screenshots

✅ Valid Results

Balanced input → result 2	Short array → result 2
Long array → result 6	All zeroes → result 0

🚫 Input Validation

Spacing error	Invalid format
Only 0/1 allowed	Letter input error

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👤 Contributor

Created with ❤️ by malakmohamed217

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