[leetcode]Backspace String Compare

简单题。注意python的s[:-1]在s == ''时，也是生效的。（返回''）

class Solution:
    def backspaceCompare(self, S: str, T: str) -> bool:
        normS = self.normalize(S)
        normT = self.normalize(T)
        return normS == normT

    def normalize(self, s: str) -> str:
        normStr = ''
        for char in s:
            if char == '#':
                normStr = normStr[:-1]
            else:
                normStr += char
        return normStr