length-of-last-word

题目：

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”,
return5.

程序：

class Solution {public:    int lengthOfLastWord(const char *s) {        int count = 0;        int len = strlen(s);//反向查找，末尾空格忽略，行中出现空格就终止循环        for(int i = len-1; i >= 0 ; i--){            if(s[i] == ' '){                if(count)                    break;            }            else{                count++;            }        }        return count;    }};

点评：

不能创建多余的空间，增加空间复杂度，会导致段错误