输入若干行正文，输出其中含有给定单词的那些行

是在贴吧看到的一个问题，代码如下，一如既往void foo (in{

 auto str = to_string (i); cout << "The length is: " << str.length () << endl; cout << str << endl; cout << string (str.crbegin (), str.crend ()); } vector<vector<string>> matchLines (map<size_t, vector<string>> content, string keyWord) { vector<vector<string>> result; bool matchTheKeyWord = false; for (const auto &record : content) { for (const auto &word : record.second) { if (word == keyWord) { matchTheKeyWord = true; break; } } if (matchTheKeyWord) { result.push_back (record.second); matchTheKeyWord = false; } } return move (result); } void foo () { size_t lineNo = 0; string line; map<size_t, vector<string>> inputContent; while (getline (cin, line)) { stringstream wordStream (line); string word; vector<string> words; while (wordStream >> word) { words.push_back (word); } ++lineNo; inputContent.insert (make_pair (lineNo, words)); } cout << "Input your key word: "; string keyWord; cin.clear(); clearerr(stdin)； cin >> keyWord; auto result = matchLines (inputContent, keyWord); for (const auto & line : result) { for (const auto &word : line) { cout << word << " "; } cout << endl; } }