Length of Last Word(返回最后一个字母的长度)

题目描述：

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

.

思路：

返回最后一个单词的长度，从后遍历整个字符串，遇到空格跳出，不遇到空格，变量加1.

代码实现：

class Solution {
public:
int lengthOfLastWord(string s) {
int len=s.length();
int i=len-1;
int j=0;
while(i>=0 && s[i]==' ')
{
i--;
}
while(i>=0 && s[i]!=' ')
{
i--;
j++;
}
return j;
}
};