Balanced Stretch

Difficulty: 1500 3000 ms 128 MB

prefix-sums

In a 0/1 array, find the length of the longest contiguous subarray containing equally many 0s and 1s.

Input: the first line has N; the second line has N values (0 or 1).

Output: the longest balanced subarray length (0 if none).

Constraints:

• 1 ≤ N ≤ 10⁵

Sample Tests

6
0 1 0 0 1 1

6

2
1 1

0

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