leetcode Reverse Words in a String

将句子的词反转，例如：

Given s = "the sky is blue",
return "blue is sky the".

思路：就是从后面往前，找到非空格的长度，然后取到另一个串中。遍历一次就可以了。如下：

class Solution {
public:
    void reverseWords(string &s) {
        if (s.size() < 1) return ;
        int ind = s.size() - 1, wordLen = 0, tmpind;
        string ans = "";
        while(ind >=0)
        {
            wordLen = 0;
            while(ind >= 0 && s[ind] == ' ') ind--;
            tmpind = ind;
            while(ind >= 0 && s[ind] != ' ') ind--;
            wordLen = tmpind - ind;
            if (wordLen > 0)
            {
                if (ans.size() == 0)
                    ans = s.substr(ind + 1, wordLen);
                else
                    ans = ans + ' ' + s.substr(ind + 1, wordLen);
            }
            ind--;
        }
        s = ans;
    }
};

这次又出现 unlock the question，然后评分