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.

int lengthOfLastWord(string s) {        int len = s.length();        int count = 0;        for(int i = len - 1; i >= 0; i--){            if(i < len -1 && s[i] == ' ' && s[i+1] != ' ' )                break;            if(s[i]!=' '){                count++;            }        }        return count;    }

改进的代码：

int lengthOfLastWord(string s) {        int len = 0, tail = s.length() - 1;        while (tail >= 0 && s[tail] == ' ') tail--;//去除末尾的空格        while (tail >= 0 && s[tail] != ' ') {            len++;            tail--;        }        return len;    }