leetcode-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.

思路：从后到前遍历得到最后一个word长度。注意最后可能有一系列空格，先清除

class Solution {public:    int lengthOfLastWord(string s) {        int length = 0;        int i = s.size()-1;        while(s[i] == ' ')        {            i--;        }        for(;i >= 0;i--)        {            if(s[i] == ' ')            {                return length;            }            length++;        }        return length;    }};