58. Length of Last Word

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

.

注意这样的“a   ”,最后一个字符串是a。所以先要去掉末尾的空格。

class Solution {
public:
int lengthOfLastWord(string s) {
int cnt = 0;
int len = s.size()-1;
while (len>=0&&s[len] == ' '){//去掉末尾的空格
len--;
}
while(len>=0&&s[len]!=' '){
len--;
cnt++;
}
return cnt;
}
};