Finish Chapter 11

Author: yyin-dev

ch11/Sales_data.h

@@ -0,0 +1,71 @@
+#ifndef SALES_DATA_H
+#define SALES_DATA_H
+
+#include <iostream>
+#include <fstream>
+#include <string>
+
+struct Sales_data;
+std::istream& read(std::istream& is, Sales_data& data);
+// Do not need to overload the read() function to take parameter of std::ifstream or std::fstream.
+// They inherit from std::istream and polymorphism applies. 
+
+class Sales_data {
+    friend Sales_data add(Sales_data& data1, Sales_data& data2);
+    friend std::istream& read(std::istream& is, Sales_data& data);
+    friend std::ostream& print(std::ostream& os, const Sales_data & data);
+
+    std::string bookNo;
+    unsigned units_sold = 0;
+    double revenue = 0.0;
+
+   public:
+    Sales_data() = default;
+    Sales_data(const std::string& s, unsigned n, double p) : bookNo(s), units_sold(n), revenue(n * p) {}
+    Sales_data(const std::string& s) : bookNo(s) {}
+    Sales_data(std::istream& is);
+
+    const std::string isbn() const { return bookNo; }
+    Sales_data& combine(const Sales_data&);
+    double avg_price() const;
+};
+
+// define constructors
+Sales_data::Sales_data(std::istream& is) {
+    read(is, *this);
+}
+
+// define member function
+Sales_data& Sales_data::combine(const Sales_data& that) {
+    units_sold += that.units_sold;
+    revenue += that.revenue;
+    return *this;
+}
+
+double Sales_data::avg_price() const {
+    if (units_sold) {
+        return revenue / units_sold;
+    }
+    return 0.0;
+}
+
+// define non member functions
+Sales_data add(Sales_data& data1, Sales_data& data2) {
+    Sales_data sum = data1;
+    sum.combine(data2);
+    return sum;
+}
+
+std::istream& read(std::istream& is, Sales_data& data) {
+    double price;
+    is >> data.bookNo >> data.units_sold >> price;
+    data.revenue = price * data.units_sold;
+    return is;
+}
+
+std::ostream& print(std::ostream& os, const Sales_data& data) {
+    os << data.isbn() << " " << data.units_sold << " " << data.avg_price() << std::endl;
+    return os;
+}
+
+#endif

ch11/ex11_10.cpp

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+#include "headers.h"
+
+bool int_vector_iter_comp(const vector<int>::iterator iter1, const vector<int>::iterator iter2) {
+    return *iter1 < *iter2;
+}
+
+bool int_list_iter_comp(const list<int>::iterator iter1, const list<int>::iterator iter2) {
+    return *iter1 < *iter2;
+}
+
+int main() {
+    // 1. Test vector<int>::iterator as key type
+
+    // Without providing custom comparison function
+    map<vector<int>::iterator, int> default_comparison;
+
+    // Providing custom comparison function, check C++ Primer p247
+    // Basic version
+    map<vector<int>::iterator, int,
+        bool (*)(const vector<int>::iterator iter1, const vector<int>::iterator iter2)>
+        basic(int_vector_iter_comp);
+
+    // use decltype
+    map<vector<int>::iterator, int, decltype(int_vector_iter_comp)*> with_decltype(&int_vector_iter_comp);
+
+    // Use type alias or using
+    typedef bool my_predicate(const vector<int>::iterator iter1, const vector<int>::iterator iter2);
+    map<vector<int>::iterator, int, my_predicate*> with_typedef(&int_vector_iter_comp);
+
+    using my_predicate_pointer_type = bool (*)(const vector<int>::iterator iter1, const vector<int>::iterator iter2);
+    map<vector<int>::iterator, int, my_predicate_pointer_type> with_using(&int_vector_iter_comp);
+
+    vector<int> v = {1, 2, 3};
+
+    default_comparison.insert(pair<vector<int>::iterator, int>({v.end(), 0}));
+    default_comparison.insert(pair<vector<int>::iterator, int>({v.begin(), 0}));
+    default_comparison.insert(pair<vector<int>::iterator, int>({v.begin(), 1}));
+    default_comparison.insert(pair<vector<int>::iterator, int>({v.begin() + 1, 1}));
+
+    cout << "size: " << default_comparison.size() << endl;
+    for (auto& p : default_comparison) {
+        cout << *(p.first) << ": " << p.second << endl;
+    }
+
+    basic.insert(pair<vector<int>::iterator, int>({v.end(), 0}));
+    basic.insert(pair<vector<int>::iterator, int>({v.begin(), 0}));
+    basic.insert(pair<vector<int>::iterator, int>({v.begin(), 1}));
+    basic.insert(pair<vector<int>::iterator, int>({v.begin() + 1, 1}));
+
+    cout << "size: " << basic.size() << endl;
+    for (auto& p : basic) {
+        cout << *(p.first) << ": " << p.second << endl;
+    }
+
+    with_decltype.insert(pair<vector<int>::iterator, int>({v.end(), 0}));
+    with_decltype.insert(pair<vector<int>::iterator, int>({v.begin(), 0}));
+    with_decltype.insert(pair<vector<int>::iterator, int>({v.begin(), 1}));
+    with_decltype.insert(pair<vector<int>::iterator, int>({v.begin() + 1, 1}));
+
+    cout << "size: " << with_decltype.size() << endl;
+    for (auto& p : with_decltype) {
+        cout << *(p.first) << ": " << p.second << endl;
+    }
+
+    with_typedef.insert(pair<vector<int>::iterator, int>({v.end(), 0}));
+    with_typedef.insert(pair<vector<int>::iterator, int>({v.begin(), 0}));
+    with_typedef.insert(pair<vector<int>::iterator, int>({v.begin(), 1}));
+    with_typedef.insert(pair<vector<int>::iterator, int>({v.begin() + 1, 1}));
+
+    cout << "size: " << with_typedef.size() << endl;
+    for (auto& p : with_typedef) {
+        cout << *(p.first) << ": " << p.second << endl;
+    }
+
+    // 2. Test list<int>::iterator as key type
+    map<list<int>::iterator, int> my_map;
+    map<list<int>::iterator, int, decltype(int_list_iter_comp)*> my_map2;
+
+    list<int> l{1, 2, 3};
+
+    // my_map.insert(pair<list<int>::iterator, int>({l.begin(), 1}));  // Error, as list<int>::iterator has no < operator defined
+    my_map2.insert(pair<list<int>::iterator, int>({l.begin(), 1}));    // ok, if you supply the comparison function
+}

ch11/ex11_12.cpp

@@ -0,0 +1,14 @@
+#include "headers.h"
+
+int main() {
+    string s;
+    int i;
+    vector<pair<string,int>> v;
+    while(cin >> s >> i){
+        pair<string, int> p{s, i};
+        v.push_back(p);
+    }
+    for (auto &p : v){
+        cout << p.first << "-" << p.second << endl;
+    }
+}

ch11/ex11_14.cpp

@@ -0,0 +1,34 @@
+#include "headers.h"
+
+using name_birthday_pair = pair<string, string>;
+
+void new_family(map<string, vector<name_birthday_pair>> &family_book, const string &lastname, const vector<name_birthday_pair> &children) {
+    family_book[lastname] = children;
+}
+
+void new_children(map<string, vector<name_birthday_pair>> &family_book, const string &lastname, const vector<name_birthday_pair> &new_children) {
+    for (auto &c : new_children) {
+        family_book[lastname].push_back(c);
+    }
+}
+
+void print_family_book(map<string, vector<name_birthday_pair>> family_book) {
+    for (auto &p : family_book) {
+        cout << "[Family] " << p.first << ": ";
+        for (auto &name_birthday_p : p.second) {
+            cout << name_birthday_p.first << "(" << name_birthday_p.second  << "), ";
+        }
+        cout << endl;
+    }
+}
+
+int main() {
+    map<string, vector<name_birthday_pair>> family_book;
+
+    new_family(family_book, "James", {make_pair("Bronny", "2001-01-01"), make_pair("Bryce", "2005-01-01"), make_pair("Jr.", "2007-01-01")});
+    new_family(family_book, "Bryant", {make_pair("Natalie", "2002-01-01"), make_pair("Bianka", "2006-01-01"), make_pair("Gianna.", "2008-01-01")});
+    print_family_book(family_book);
+    cout << "[News] New children to Bryant's family!" << endl;
+    new_children(family_book, "Bryant", {make_pair("Capri", "2017-01-01")});
+    print_family_book(family_book);
+}

ch11/ex11_15.cpp

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+#include "headers.h"
+#include "Sales_data.h"
+
+bool compareIsbn(const Sales_data &d1, const Sales_data & d2){
+    return d1.isbn() < d2.isbn();
+}
+
+int main() {
+    multiset<Sales_data, decltype(compareIsbn) *> bookstore(compareIsbn);
+
+    multiset<Sales_data, decltype(compareIsbn) *>::const_iterator iter = bookstore.begin();
+}

ch11/ex11_23.cpp

@@ -0,0 +1,25 @@
+#include "headers.h"
+
+using name_birthday_pair = pair<string, string>;
+
+void new_family(multimap<string, vector<name_birthday_pair>> &family_book, const string &lastname, const vector<name_birthday_pair> &children) {
+    family_book.insert({lastname, children});
+}
+
+void print_family_book(multimap<string, vector<name_birthday_pair>> family_book) {
+    for (auto &p : family_book) {
+        cout << "[Family] " << p.first << ": ";
+        for (auto &name_birthday_p : p.second) {
+            cout << name_birthday_p.first << "(" << name_birthday_p.second << "), ";
+        }
+        cout << endl;
+    }
+}
+
+int main() {
+    multimap<string, vector<name_birthday_pair>> family_book;
+
+    new_family(family_book, "James", {make_pair("Bronny", "2001-01-01"), make_pair("Bryce", "2005-01-01"), make_pair("Jr.", "2007-01-01")});
+    new_family(family_book, "Bryant", {make_pair("Natalie", "2002-01-01"), make_pair("Bianka", "2006-01-01"), make_pair("Gianna.", "2008-01-01")});
+    print_family_book(family_book);
+}

ch11/ex11_26.cpp

@@ -0,0 +1,11 @@
+#include "headers.h"
+
+int main() {
+    map<int, string> m = {{1, "ss"}, {2, "sz"}};
+    using KeyType = map<int, std::string>::key_type;
+
+    cout << "type to subscript: " << typeid(KeyType).name() << endl;
+    cout << "returned from the subscript operator: " << typeid(decltype(m[1])).name() << endl;
+
+    return 0;
+}

ch11/ex11_28.cpp

@@ -0,0 +1,7 @@
+#include "headers.h"
+
+int main(){
+
+    map<string, vector<int>> m;
+    map<string, vector<int>>::iterator found_iter = m.find("hi");
+}

ch11/ex11_3.cpp

@@ -0,0 +1,18 @@
+#include "headers.h"
+
+int main() {
+    map<string, int> counting_book;
+    set<string> exculsion_set = {"and", "but", "or"};
+
+    ifstream ifs("./word_count_input.txt");
+    string word;
+    while (ifs >> word) {
+        if (exculsion_set.find(word) == exculsion_set.end()) {
+            ++counting_book[word];
+        }
+    }
+
+    for (auto &kv_pair : counting_book) {
+        cout << kv_pair.first << ": " << kv_pair.second << "; " << endl;
+    }
+}

ch11/ex11_31.cpp

@@ -0,0 +1,30 @@
+#include "headers.h"
+
+void find_and_erase(multimap<string, string> &m, string k) {
+    auto iter = m.find(k);
+    if (iter == m.end()) {
+        cout << "Element not found!\n";
+    } else {
+        m.erase(iter);
+        cout << "Element with value: " << iter -> second << " found and erased!\n";
+    }
+}
+
+int main() {
+    using author_work_type = pair<string, string>;
+    multimap<string, string> m{
+        author_work_type{"Shakespear", "King Lear"},
+        author_work_type{"Marquez", "One hundred years of solitude"},
+        author_work_type{"Marquez", "Love in the Time of Cholera"},
+        author_work_type{"Shakespear", "Macbeth"},
+        author_work_type{"Shakespear", "Hamlet"},
+        author_work_type{"Yu Hua", "A life"},
+        author_work_type{"Hemingway", "The sun also rises"},
+        author_work_type{"Hemingway", "A fareware to arms"},
+    };
+
+    // erase
+    find_and_erase(m, "Shakespear");
+    cout << m.find("Shakespear") -> second << endl;
+    find_and_erase(m, "Fred");
+}