题解 | #HJ31 单词倒排#

方法1

s = input()
new_s = ""
for i in s:
    if 97 <= ord(i.lower()) <= 122:
        new_s += i
    else:
        new_s += " "
arr = new_s.split()
print(" ".join(arr[::-1]))

方法2

a = input()
for i in a:
    if not 97 <= ord(i.lower()) <= 122:
        a = a.replace(i, " ")
b = a.split()
print(*b[::-1])

方法3

s = input().strip() + " "
word = ''
word_list = []
for c in s:
    if c.isalpha():
        word += c
    else:
        word_list.append(word)
        word = ''
print(' '.join(word_list[::-1]))

注意：使用split()而不是split(' ')，因为如果两字母间存在多个空格时，空格也会被分割出来，而题目要求只允许出现一个空格。