151. Reverse Words in a String

题目描述：

Example:  

Input: "the sky is blue",
Output: "blue is sky the".

Note:

• A word is defined as a sequence of non-space characters.
• Input string may contain leading or trailing spaces. However, your reversed string should not contain leading or trailing spaces.
• You need to reduce multiple spaces between two words to a single space in the reversed string.

Follow up: For C programmers, try to solve it in-place in O(1) space.

解题思路：

题目不难，直接代码

代码：

class Solution {
public:
    void reverseWords(string &s) {
        reverse(s.begin(), s.end());
        istringstream sin(s);
        string word, res;
        while (sin>>word) {
            reverse(word.begin(), word.end());
            res += word;
            res += " ";
        }
        if (res.size() > 0)
            res.erase(res.size() - 1, 1);
        s = res;
    }
};