www.gusucode.com > C++ Primer 书籍源代码源码程序 > C++ Primer 书籍源代码源码程序/code/10/TextQuery.cpp
//Download by http://www.NewXing.com /* * This file contains code from "C++ Primer, Fourth Edition", by Stanley B. * Lippman, Jose Lajoie, and Barbara E. Moo, and is covered under the * copyright and warranty notices given in that book: * * "Copyright (c) 2005 by Objectwrite, Inc., Jose Lajoie, and Barbara E. Moo." * * * "The authors and publisher have taken care in the preparation of this book, * but make no expressed or implied warranty of any kind and assume no * responsibility for errors or omissions. No liability is assumed for * incidental or consequential damages in connection with or arising out of the * use of the information or programs contained herein." * * Permission is granted for this code to be used for educational purposes in * association with the book, given proper citation if and when posted or * reproduced.Any commercial use of this code requires the explicit written * permission of the publisher, Addison-Wesley Professional, a division of * Pearson Education, Inc. Send your request for permission, stating clearly * what code you would like to use, and in what specific way, to the following * address: * * Pearson Education, Inc. * Rights and Contracts Department * 75 Arlington Street, Suite 300 * Boston, MA 02216 * Fax: (617) 848-7047 */ #include "TextQuery.h" #include <sstream> #include <string> #include <vector> #include <map> #include <set> #include <iostream> #include <fstream> #include <cctype> #include <cstring> #include <stdexcept> using std::istringstream; using std::set; using std::string; using std::getline; using std::map; using std::vector; using std::cerr; using std::cout; using std::cin; using std::ifstream; using std::endl; using std::ispunct; using std::tolower; using std::strlen; using std::out_of_range; string TextQuery::text_line(line_no line) const { if (line < lines_of_text.size()) return lines_of_text[line]; throw std::out_of_range("line number out of range"); } // read input file: store each line as element in lines_of_text void TextQuery::store_file(ifstream &is) { string textline; while (getline(is, textline)) lines_of_text.push_back(textline); } // \v: vertical tab; \f: formfeed; \r: carriage return are // treated as whitespace characters along with space, tab and newline string TextQuery::whitespace_chars(" \t\n\v\r\f"); // finds whitespace-separated words in the input vector // and puts the word in word_map along with the line number void TextQuery::build_map() { // process each line from the input vector for (line_no line_num = 0; line_num != lines_of_text.size(); ++line_num) { // we'll use line to read the text a word at a time istringstream line(lines_of_text[line_num]); string word; while (line >> word) // add this line number to the set; // subscript will add word to the map if it's not already there word_map[cleanup_str(word)].insert(line_num); } } set<TextQuery::line_no> TextQuery::run_query(const string &query_word) const { // Note: must use find and not subscript the map directly // to avoid adding words to word_map! map<string, set<line_no> >::const_iterator loc = word_map.find(cleanup_str(query_word)); if (loc == word_map.end()) return set<line_no>(); // not found, return empty set else // fetch and return set of line numbers for this word return loc->second; } void TextQuery::display_map() { map< string, set<line_no> >::iterator iter = word_map.begin(), iter_end = word_map.end(); // for each word in the map for ( ; iter != iter_end; ++iter) { cout << "word: " << iter->first << " {"; // fetch location vector as a const reference to avoid copying it const set<line_no> &text_locs = iter->second; set<line_no>::const_iterator loc_iter = text_locs.begin(), loc_iter_end = text_locs.end(); // print all line numbers for this word while (loc_iter != loc_iter_end) { cout << *loc_iter; if (++loc_iter != loc_iter_end) cout << ", "; } cout << "}\n"; // end list of output this word } cout << endl; // finished printing entire map } string TextQuery::cleanup_str(const string &word) { string ret; for (string::const_iterator it = word.begin(); it != word.end(); ++it) { if (!ispunct(*it)) ret += tolower(*it); } return ret; }