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//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 "assoc_preamble.h" #include <map> int main() { // count number of times each word occurs in the input map<string, int> word_count; // empty map from string to int string word; while (cin >> word) ++word_count[word]; // get iterator positioned on the first element map<string, int>::const_iterator map_it = word_count.begin(); // for each element in the map while (map_it != word_count.end()) { // print the element key, value pairs cout << map_it->first << " occurs " << map_it->second << " times" << endl; ++map_it; // increment iterator to denote the next element } return 0; } // Alternative implementation using insert instead of subscript void alt_word_count() { // count number of times each word occurs in the input map<string, int> word_count; // empty map from string to int string word; while (cin >> word) { // inserts element with key equal to word and value 1; // if word already in word_count, insert does nothing pair<map<string, int>::iterator, bool> ret = word_count.insert(make_pair(word, 1)); if (!ret.second) // word already in word_count ++ret.first->second; // increment counter } }