C++ primer习题记录——第十一章

11.3：

#include <iostream>
using namespace std;
#include<map>
#include<set>
int main()
{
    map<string, size_t>words_count;
    string word;
    set<string>ss = { "the","an","a" };
    while (cin >> word)
    {
        if (ss.find(word) == ss.end())
        {
            ++words_count[word];
        }
    }
    for (const auto& s : words_count)
    {
        cout << s.first << " occur " << s.second <<
            ((s.second > 1) ? "times" : "time") << endl;
    }
    return 0;
}

11.4:

#include <iostream>
using namespace std;
#include<map>
#include<set>

int main()
{
    map<string, size_t>words_count;
    string word;
    while (cin >> word)
    {
        for (auto& c : word)
        {
            c = tolower(c);
        }
        word.erase(remove_if(word.begin(), word.end(), ispunct), word.end());
        ++words_count[word];
    }
    for (const auto& s : words_count)
    {
        cout << s.first << " occur " << s.second <<
            ((s.second > 1) ? " times" : " time") << endl;
    }
    return 0;
}

10.7：

#include <iostream>
using namespace std;
#include<map>
#include<vector>
int main()
{
    map<string, vector<string>>family;  
    for (string secondname; cout << "请输入姓： ", cin >> secondname&&secondname!="end";)
    {
        for (string firstname; cout << "请输入名： ", cin >> firstname&&firstname!="end";)
        {
            family[secondname].push_back(firstname);
        }
    }
    for (auto f : family)
    {
        for (auto f2 : f.second)
        {
            cout << f.first << " " << f2 << endl;
        }
    }
    return 0;
}

11.8：

#include <iostream>
using namespace std;
#include<vector>
int main()
{
    vector<string>words;
    for (string word; cout << "请输入单词： ", cin >> word;)
    {
        if (find(words.cbegin(), words.cend(), word) == words.cend())
        {
            words.push_back(word);
        }
        else
        {
            cout << "已有重复单词" << endl;
        }
    }
    return 0;
}

11.13：

#include <iostream>
using namespace std;
#include<vector>

int main()
{
    vector<pair<string, int>>vep;
    string str;
    int i = 0;
    while (cin >> str >> i)
    {
        vep.push_back(make_pair(str, i));
        vep.push_back(pair<string, int>(str, i));
        vep.push_back({ str,i });
        vep.emplace_back(str, i);
    }
    return 0;
}

11.14：

#include <iostream>
using namespace std;
#include<map>
#include<vector>
int main()
{
    map<string, vector<pair<string,string>>>family;
    for (string secondname; cout << "请输入姓： ", cin >> secondname && secondname != "end";)
    {
        for (string firstname; cout << "请输入名： ", cin >> firstname && firstname != "end";)
        {
            cout << "请输入生日： ";
            string birthday;
            cin >> birthday;
            family[secondname].push_back(make_pair(firstname,birthday));
        }
    }
    for (auto f : family)
    {
        for (auto f2 : f.second)
        {
            cout << f.first << " " << f2.first << " " << f2.second << endl;
        }
    }
    return 0;
}

11.16：

#include <iostream>
using namespace std;
#include<map>

int main()
{
    map<int, int>m;
    m[1] = 2;
    auto beg = m.begin();
    cout << beg->first << " " << beg->second << endl;
    beg->second = 1;
    cout << beg->first << " " << beg->second << endl;
    return 0;
}

11.20：

#include <iostream>
using namespace std;
#include<map>
#include<set>
int main()
{
    map<string, size_t>words_count;
    string word;
    while (cin >> word)
    {
        auto it = words_count.insert({ word,1 });
        if (!it.second)
        {
            ++it.first->second;
        }
    }
    for (const auto& s : words_count)
    {
        cout << s.first << " occur " << s.second <<
            ((s.second > 1) ? "times" : "time") << endl;
    }
    return 0;
}

11.23：

#include <iostream>
using namespace std;
#include<map>

int main()
{
    multimap<string, string>families;
    string fname, lname;
    while (cin >> fname >> lname)
    {
        families.insert({ fname,lname });
    }
    for (auto f : families)
    {
        cout << f.first << " " << f.second << endl;
    }
    return 0;
}

11.26：

#include <iostream>
#include <map>
#include <string>
#include <typeinfo>

int main()
{
    // ex11.26
    std::map<int, std::string> m = { { 1,"ss" },{ 2,"sz" } };
    using KeyType = std::map<int, std::string>::key_type;

    std::cout << "type to subscript: " << typeid(KeyType).name() << std::endl;
    std::cout << "returned from the subscript operator: " << typeid(decltype(m[1])).name() << std::endl;

    return 0;
}

11.31：

第一版：

#include <iostream>
using namespace std;
#include <map>

int main()
{
    multimap<string, string>authors = { 
        {"jojo","<fly>"},
        {"jojo","<jump>"},
        {"jojo","<map>"},
        {"coco","<computer>"},
        {"coco","<chanel>"} };
   for (auto it = authors.find("jojo");it != authors.end();++it)
    {
       if (it->second == "<fly>")
       {
           authors.erase(it);
           break;
        }
    }
   for (auto m : authors)
   {
       cout << m.first << " " << m.second << endl;
   }
    return 0;
}

第二版：

#include <iostream>
using namespace std;
#include <map>

int main()
{
    multimap<string, string>authors = { 
        {"jojo","<fly>"},
        {"jojo","<jump>"},
        {"jojo","<map>"},
        {"coco","<computer>"},
        {"coco","<chanel>"} };
    auto it = authors.find("jojo");
    auto count = authors.count("jojo");
    while (count)
    {
        if (it->second == "<jump>")
        {
            authors.erase(it);
            break;
        }
        ++it;
        --count;
    }
   for (const auto& m : authors)
   {
       cout << m.first << " " << m.second << endl;
   }
    return 0;
}

11.32；

#include <iostream>
using namespace std;
#include <map>
#include<set>
int main()
{
    multimap<string, string>authors = { 
        {"jojo","<fly>"},
        {"jojo","<jump>"},
        {"jojo","<map>"},
        {"coco","<computer>"},
        {"coco","<chanel>"} };
    map<string, set<string>>oder;
    for (auto a : authors)
    {
        oder[a.first].insert(a.second);
    }
    for (auto a : oder)
    {
        for (auto b : a.second)
        {
            cout << a.first << " " << b << endl;
        }
    }
    return 0;
}

11.33：

我去，这个代码我查了好几遍，后来发现自己的return写在while里面了，吐血

#include <map>
#include <string>
#include <fstream> 
#include <iostream>
#include <sstream>

using std::string; using std::ifstream;

std::map<string, string> buildMap(ifstream& map_file)
{
    std::map<string, string> trans_map;
    for (string key, value; map_file >> key && getline(map_file, value); )
        if (value.size() > 1) trans_map[key] = value.substr(1).substr(0, value.find_last_not_of(' '));
    return trans_map;
}

const string& transform(const string& s, const std::map<string, string>& m)
{
    auto map_it = m.find(s);
    return map_it == m.cend() ? s : map_it->second;
}

void word_transform(ifstream& map, ifstream& input)
{
    auto trans_map = buildMap(map);
    for (string text; getline(input, text); ) {
        std::istringstream iss(text);
        for (string word; iss >> word; )
            std::cout << transform(word, trans_map) << " ";
        std::cout << std::endl;
    }
}

int main()
{
    ifstream ifs_map("1.txt"), ifs_content("2.txt");
    if (ifs_map && ifs_content) word_transform(ifs_map, ifs_content);
    else std::cerr << "can't find the documents." << std::endl;
}

#include <iostream>
using namespace std;
#include <map>
#include<fstream>
#include<string>
#include<sstream>

map<string, string> buildMap(ifstream& map_file)
{
    map<string, string>trans_map;
    string key, value;
    while (map_file >> key && getline(map_file, value))
    {
        if (value.size() > 1)
        {
            trans_map[key] = value.substr(1).substr(0, value.find_last_not_of(' '));
        }
       
    }
    return trans_map;
}
const string& transform(const string& s, const map<string, string>& m)
{
    auto map_it = m.find(s);
    if (map_it != m.cend())
    {
        return map_it->second;
    }
    else
    {
        return s;
    }
}

void word_transform(ifstream& map_file, ifstream& input)
{
    auto trans_map = buildMap(map_file);
    string text;
    while (getline(input, text))
    {
        istringstream stream(text);
        string word;
        bool firstword = true;
        while (stream >> word)
        {
            if (firstword)
            {
                firstword = false;
            }
            else
            {
                cout << " ";
            }
            cout << transform(word, trans_map);
        }
        cout << endl;
    }
}

int main()
{
    ifstream ifs_map("1.txt"), ifs_content("2.txt");
  
        word_transform(ifs_map, ifs_content);
   
    return 0;
}

11.38：

#include <unordered_map>
#include <set>
#include <string>
#include <iostream>
#include <fstream>
#include <sstream>

using std::string;

void wordCounting()
{
    std::unordered_map<string, size_t> word_count;
    for (string word; std::cin >> word; ++word_count[word]);
    for (const auto &w : word_count)
        std::cout << w.first << " occurs " << w.second << (w.second > 1 ? "times" : "time") << std::endl;
}

void wordTransformation()
{
    std::ifstream ifs_map("../data/word_transformation.txt"), ifs_content("../data/given_to_transform.txt");
    if (!ifs_map || !ifs_content) {
        std::cerr << "can't find the documents." << std::endl;
        return;
    }
    
    std::unordered_map<string, string> trans_map;
    for (string key, value; ifs_map >> key && getline(ifs_map, value); )
        if (value.size() > 1) trans_map[key] = value.substr(1).substr(0, value.find_last_not_of(' '));
    
    for (string text, word; getline(ifs_content, text); std::cout << std::endl)
        for (std::istringstream iss(text); iss >> word; ) {
            auto map_it = trans_map.find(word);
            std::cout << (map_it == trans_map.cend() ? word : map_it->second) << " ";
        }
}

int main()
{
    //wordCounting();
    wordTransformation();
}