题解 | #字符串变形#

#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param s string字符串 
# @param n int整型 
# @return string字符串
#
class Solution:
    def trans(self , s: str, n: int) -> str:
        # write code here
        if n == 0:
            return s
        rsta = ""

        for i in range(n):
            # 大小写转换
            if s[i] <= 'Z' and s[i] >= 'A':
                rsta += chr(ord(s[i]) - ord('A') + ord('a'))
            elif s[i] >= 'a' and s[i] <= 'z':
                rsta += chr(ord(s[i]) - ord('a') + ord('A'))
            else:
                # 空格复制
                rsta += s[i]
        # 单词反序
        rsta = list(rsta.split(" "))[::-1]
        return ' '.join(rsta)