ORIGINAL CODING QUESTION
Longest balanced flag span
Return the longest contiguous span containing equally many zeros and ones.
Original exercise · medium. Editorial role relevance does not imply a company has asked this question.
Input and output
n, then n integer values. Print one integer as described.
Constraints
1 ≤ n ≤ 200; flags are 0 or 1.
Example 1
Input
4 0 1 0 1
Output
4
The entire array is balanced.
Example 2
Input
3 1 1 1
Output
0
No nonempty balanced span exists.
Explain your approach
Explain your time and auxiliary space complexity. Which input makes your algorithm work hardest?
Private grading inputs, expected outputs and canonical reference implementations are withheld. Authored expected outputs were cross-checked with independent reference oracles; compiler/runtime behavior still needs a verified execution provider.
Hint 1
Treat zero as -1 and one as +1.
Hint 2
Equal prefix balances identify a balanced span.
Hint 3
Keep the earliest index for every balance.
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