1963. Minimum Number of Swaps to Make The String Balanced - Explanation

class Solution:
    def minSwaps(self, s: str) -> int:
        stack = []
        for c in s:
            if c == '[':
                stack.append(c)
            elif stack:
                stack.pop()
        return (len(stack) + 1) // 2

class Solution:
    def minSwaps(self, s: str) -> int:
        close = maxClose = 0

        for c in s:
            if c == '[':
                close -= 1
            else:
                close += 1
            maxClose = max(maxClose, close)

        return (maxClose + 1) // 2

class Solution:
    def minSwaps(self, s: str) -> int:
        stackSize = 0
        for c in s:
            if c == '[':
                stackSize += 1
            elif stackSize > 0:
                stackSize -= 1
        return (stackSize + 1) // 2