You are given a string S of 2N characters consisting of N ‘[‘ brackets and N ‘]’ brackets. A string is considered balanced if it can be represented in the form S2[S1] where S1 and S2 are balanced strings. We can make an unbalanced string balanced by swapping adjacent characters.
Calculate the minimum number of swaps necessary to make a string balanced.
Note - Strings S1 and S2 can be empty.
Example 1:
Input : []][][
Output : 2
Explanation :
First swap: Position 3 and 4
[][]][
Second swap: Position 5 and 6
[][][]
Example 2:
Input : [[][]]
Output : 0
Explanation:
String is already balanced.

Your Task:
You don't need to read input or print anything. Your task is to complete the function minimumNumberOfSwaps() which takes the string S and return minimum number of operations required to balance the bracket sequence.
Expected Time Complexity: O(N)
Expected Auxiliary Space: O(1)
Constraints:
1<=|S|<=100000

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