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.

Example:

Input: "Hello World"
Output: 5

class Solution {
public:
    int lengthOfLastWord(string s) {
        int len = 0, tail = s.length() - 1;
        while (tail >= 0 && s[tail] == ' ') tail--; //过滤掉 “ abb bb    ” 后面的空格
        while (tail >= 0 && s[tail] != ' ')
            {
                len++;
                tail--;
            }
        return len;
    }

    

};