Minimum Number of Chairs in a Waiting Room — Python

# Time:  O(n)
# Space: O(1)

# simulation
class Solution(object):
    def minimumChairs(self, s):
        """
        :type s: str
        :rtype: int
        """
        result = curr = 0
        for x in s:
            curr += +1 if x == "E" else -1
            result = max(result, curr)
        return result