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Minimum Number of Swaps to Make The String Balanced

MediumArrays

A string of even length contains equal numbers of '[' and ']'. In one move you may swap any two characters. Return the minimum number of swaps to make the string balanced (a valid bracket sequence).

Input format (stdin): a single line, the bracket string. Output the minimum swaps.

Examples
Input: ][][
Output: 1
Swap to get [][].
Input: ]]][[[
Output: 2
Two swaps suffice.
Constraints
  • 2 <= length <= 10^6
  • equal counts of '[' and ']'
Sheets
NeetCode 250
minimum-number-of-swaps-to-make-the-string-balanced.cpp3 sample tests
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Test results

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Custom input (stdin)
Output

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