用到的几个小知识 ：

1.字符串流是以空格作为一个字符串的结束标志，采用stringstream来提取单词。

2.为了消除重复单词，需要先将vector排序，使得重复的单词相邻出现，不先排序无法正确“删除”重复元素

3.使用unique STL算法来重排vector，使得不重复的元素出现在vector的开始部分。

代码如下：

#include "stdafx.h"
#include <string.h>
#include <algorithm>
#include <vector>
#include <deque>
#include <functional>
#include <iostream>
#include <list>
#include <sstream>
#include <iterator>
#include <functional>using namespace std;int _tmain(int argc, _TCHAR* argv[])
{stringstream ss;string str = "the quick red fox jumps over the slow red turtle";string strWord;vector<string> vecWords;ss.clear();ss.str(str);while (ss >> strWord){vecWords.push_back(strWord);strWord.clear();}cout << "sort before:" << endl;copy(vecWords.begin(), vecWords.end(), ostream_iterator<string>(cout, " "));cout << endl;cout << "sort after and unique before:" << endl;//从大到小排序//sort(vecWords.begin(), vecWords.end(),greater<string>());//默认是从小大的字典排序sort(vecWords.begin(), vecWords.end());copy(vecWords.begin(), vecWords.end(), ostream_iterator<string>(cout, " "));cout << endl;vector<string> vecWordsBackup(vecWords);cout << "sort and unique afer:" << endl;unique(vecWords.begin(),vecWords.end());copy(vecWords.begin(), vecWords.end(), ostream_iterator<string>(cout, " "));cout << endl;cout << "sort and unique and erase after:" << endl;vecWordsBackup.erase(unique(vecWordsBackup.begin(),vecWordsBackup.end()), vecWordsBackup.end());copy(vecWordsBackup.begin(), vecWordsBackup.end(), ostream_iterator<string>(cout, " "));cout << endl;cout << "total words:"<<vecWordsBackup.size() <<endl;return 0;
}

运行结果：