[leetcode:python]58.Length of Last Word

题目：
Given a string s consists of upper/lower-case alphabets and empty space characters ’ ‘, return the length of last word in the string.

If the last word does not exist, return 0.

Note: A word is defined as a character sequence consists of non-space characters only.

For example,
Given s = “Hello World”,
return 5.

方法一：性能52ms

class Solution(object):    def lengthOfLastWord(self, s):        """        :type s: str        :rtype: int        """        if len(s) == 0:            return 0        count = 0        str1 = s.rstrip()        for i in str1:            if i != ' ':                count += 1            else:                count = 0         return count

方法二：性能32ms

class Solution(object):    def lengthOfLastWord(self, s):        """        :type s: str        :rtype: int        """        cnt=0        for v in reversed(s):            if v.isspace():                if cnt:break            else:cnt+=1        return cnt

这里的reversed()函数：作用是逆转序列
且reversed()之后，只在第一次遍历时返回值。