c++ Primer Plus（第六版）第十六章习题，写代码之路

c++ Primer Plus（习题16.1)

//让用户输入回文的单词，就是那种倒着读和顺着读一样意思的//实现这个功能有很多方法，用了一种简单的方法#include<iostream>#include<string>using std::string;using std ::cout;using std::cin;using std::getline;using std::endl;bool Isplalindrome(const string &s);int main(){string p;cout << "Enter a plalindrome word: ";while (getline(cin, p)&&p != "q"){if (Isplalindrome(p))cout << "Yes, " << p << " is a plalindrome word!\n";elsecout << "Sorry,is not a plalindrome word!\n";cout << "Think about another word: (q to exit)";//getline(cin,p);}cout << "Bye!\n";}bool Isplalindrome(const string &s){string temp = s;//string temp(words.rbegin(), words.rend());int j = s.size();//用上面的反转迭代器更简单int i=0;for (; i <j; i++)temp[i]=s[s.size() - i-1];//因为string索引的问题，这里要减一个temp[i] = '\0';if (temp==s)return true;return false;}

c++ Primer Plus（习题16.2)

//让用户输入回文的单词，就是那种倒着读和顺着读一样意思的//前面一道题目的升级版，客户要求的//考虑输入句子，大小写等复杂的情况//感觉思路不太好，结果没什么问题，就是饶了一点#include<iostream>#include<string>#include<cctype>//处理大小写using std::string;using std::cout;using std::cin;using std::getline;using std::endl;bool Isplalindrome(const string &s);int main(){string p;cout << "Enter a plalindrome word: ";while (getline(cin, p) && p != "q"){if (Isplalindrome(p))cout << "Yes, " << p << " is a plalindrome.\n";elsecout << "Sorry,is not a plalindrome.\n";cout << "Think about another word: (q to exit)";//getline(cin,p);}cout << "Bye!\n";}bool Isplalindrome(const string &s){string temp;//这个用于存储去掉大写，和非字母字符的string类，反转后的类int i = 0;int j = s.size() - 1;for (; j>=0;j--){if (isalpha(s[j]))//判断字符是否是字母{//处理大小写字符temp.push_back(tolower(s[j]));//还是这种方法好一点i++;}}//temp[i] = '\0'; string的结尾标记没有规定是'\0'这种方法不可行string tem(temp.rbegin(), temp.rend());if (temp == tem)return true;return false;}

c++ Primer Plus（习题16.3)

//这题是修改程序清单16.3，改成从文件中读取单词，而不是从数组中 //书上已经有解决方案了，照着就ok.#include <iostream>  #include <fstream>  #include <vector>  #include <string>  #include <cstdlib>  #include <ctime>  #include <cctype>  const int NUM = 26;void Readword();std::vector<std::string> input;//全局变量省的传递参数了int main(){std::srand(std::time(0)); char play;std::cout << "Will you play a word game? <Y/N> ";std::cin >> play;play = std::tolower(play);Readword();while (play=='y'){std::string target= input[std::rand() % NUM];int length = target.length();std::string attempt(length, '-');std::string badchars;int guesses = 6;std::cout << "Guess my secret word. It has " << length << " letters, and you guess\n" << "one letter at a time. You get " << guesses << " wrong guesses.\n";std::cout << "Your word: " << attempt << std::endl;while (guesses > 0 && attempt != target){char letter;std::cout << "Guess a letter: ";std::cin >> letter;if ((badchars.find(letter) != std::string::npos) //nops是string中的最大存储字符数|| (attempt.find(letter)!= std::string::npos)){std::cout << "You already guessed that. Try again.\n";continue;}int loc = target.find(letter);//记录找到字符的位置if (loc == std::string::npos){std::cout << "Oh, bad guess!\n";--guesses;badchars +=letter;//记录到错误的那里}else{std::cout << "Good guess!\n";attempt[loc] =letter;//显示猜对的字符loc = target.find(letter, loc + 1);while (loc != std::string::npos)//显示这个单词后面相同的字符{attempt[loc] =letter;loc = target.find(letter, loc + 1);}}std::cout << "Your word: " << attempt << std::endl;if (attempt != target){if (badchars.length() > 0)std::cout << "Bad choices: " << badchars << std::endl;std::cout << guesses << " bad guesses left\n";}}if (guesses > 0)std::cout << "That's right\n";elsestd::cout << "Sorry, the word is " << target << ".\n";std::cout << "Will you play another? <Y/N> ";std::cin >> play;play = tolower(play);}std::cout << "Bye!\n";return 0;}void Readword(){std::ifstream fin;fin.open("data.txt");if(!fin.is_open()){std::cout << "Open file data.txt error!\n";exit(EXIT_FAILURE);}std::string s;//存储读取的单词while (!fin.eof()){fin>>s;input.push_back(s);//动态增加input的成员数量}fin.close();}

c++ Primer Plus（习题16.4)

//这题是熟悉stl特性，编写一个函数接受一个数组和元数个数//对数组进行排序，删除重复的值，并返回最终的元素个数//考虑到压缩元素，可以使用list模板类，书上的unique()函数也是一种提示#include<iostream>#include<list>//list模板，双向链表#include<algorithm>//迭代器std::list<long>f;int reduce(long ar[], int i);void outlong(long n) { std::cout << n << " "; }int main(){using std::cout;long test[12] = { 40,51,57,89,87,85,40,40,51,64,52,0 };int result;result = reduce(test, 12);cout << "Source array: \n";for (long x : test)//基于范围的for循环cout << x << " ";cout << "\nThe mount: " << 12;std::cout << "\nAfter sort and remove, the number is "<<result<<std::endl;cout << "After that: \n";std::for_each(f.begin(), f.end(), outlong);std::cout << "Bye!\n";return 0;}int reduce(long ar[], int i)//使用迭代器将非常其简单，不过要会choose{f.insert(f.begin(),ar, ar + i);f.sort();//排序f.unique();//压缩相同的元素return f.size();}

c++ Primer Plus（习题16.5)

//这题是上一题的泛型，可以不依赖于特定的数组类型//这就是迭代器的终极奥义，独立于类型#include<iostream>#include<algorithm>#include<string>#include<list>template<class T>int reduce(T ar[], int n);template<class T>void outlong(T n) { std::cout << n << " "; }int main(){using std::cout;cout << "Test a function,accept a type array and longth,return after reduce same elemet""mount." << std::endl;long test[12] = { 40,51,57,89,87,85,40,40,51,64,52,0 };int result;result = reduce(test, 12);cout << result<<std::endl;std::string tests[5] = { "i","m a C","+","+","student." };result = reduce(tests, 5);cout << result<<std::endl;}template<class T>int reduce(T ar[], int n){std::list<T>f;f.insert(f.begin(), ar, ar + n);f.sort();f.unique();std::cout << "After reduce and sort:\n";std::for_each(f.begin(), f.end(), outlong<T>);std::cout << std::endl;return f.size();}

c++ Primer Plus（习题16.6)

//改写程序清单12.12就是那个排队买东西的，在c primer中也有//使用stl queue 有高级的函数辅助加上一些queue 的stl功能，//很容易实现,毕竟是标准的，我们自己做的功能没那么强大#include <iostream>  #include <cstdlib>  #include <ctime>  #include <queue>class Customer{private:long arrive;int processtime;public:Customer() { arrive = processtime = 0; }void set(long when) {processtime = std::rand() % 3 + 1;arrive = when;}long when()const { return arrive; }int ptime()const { return processtime; }};typedef Customer Item;const int MIN_PER_HR = 60;bool newcustomer(double x);int main(){using namespace std;srand(time(0));cout << "Case Study: Bank of Heather Automatic Teller\n";cout << "Enter maximum size of queue: ";//最大的排队人数int qs;cin >> qs;queue <Item>line;//queue本人没看到指定队列数的构造函数cout << "Enter the number of simulation hours: ";//测试的时间int hours;cin >> hours;long cyclelimit = MIN_PER_HR*hours;cout << "Enter the average number of cunstomers per hour: ";//每小时的额客户数double perhour;cin >> perhour;double min_per_cust;min_per_cust = MIN_PER_HR / perhour;//记录总的分钟数Item temp;long turnaways = 0;//拒绝人数long customers = 0;//来的人数long served = 0;//服务人数long sum_line = 0;//队列的长度int wait_time = 0;//取款机空闲的等待时间long line_wait = 0;//队列的总等待时间for (long cycle = 0; cycle < cyclelimit; cycle++){if (newcustomer(min_per_cust)){if (line.size()==qs)//检查队列的长度是否等于最大排队人数turnaways++;else {customers++;temp.set(cycle);line.push(temp);//enqueue和push同样的方法}}if (wait_time <= 0 && !line.empty()){line.pop();//弹出，不需要item参数wait_time = temp.ptime();line_wait += cycle - temp.when();served++;}if (wait_time > 0)wait_time--;sum_line += (line.size()) / 2;}if (customers > 0) {cout << "customers accepted: " << customers << endl;cout << "  customers served: " << served << endl;cout << "        turnaways: " << turnaways << endl;cout << "average queue size: ";cout.precision(2);cout.setf(ios_base::fixed, ios_base::floatfield);cout << (double)sum_line / cyclelimit << endl;cout << "average wait time: " << (double)line_wait / served << " minutes\n";}elsecout << "No customers!\n";cout << "Done!\n";return 0;}bool newcustomer(double x){return (rand()*x / RAND_MAX < 1);}

c++ Primer Plus（习题16.7)

//一个彩票卡的游戏，本人没听说过，//也是设计一个函数，要求使用vector容器//额，程序每次运行获取的值都一样，这要是真是中奖的程序，等着骂吧#include<iostream>#include<vector>#include<algorithm>using namespace std;vector<int> Lotto(int count, int ccount);//返回一个包含vector//从第一个参数随机选择第二个参数数量值的对象int main(){cout << "This is a Lottery card Test program.""To test a funtion Lotto: \n";vector<int>winners;int numb, times;cout << "Enter a draw range: ";cin >> numb;cout << "How many times your draw less than: ";cin >> times;winners = Lotto(numb,times);cout<< "The winners Lottery card winning number is:\n";for (auto m = winners.begin(); m != winners.end(); m++)    //用迭代器的方式输出容器对象的值{cout<< *m << endl;}cout << "Good lucky!\n";cout << "Test complete!\n";return 0;}vector<int> Lotto(int count, int ccount){vector<int>pvalue(count);//用来记录可能值,用了指定元素个数的f方法vector<int>value;//用于返回for (int i = 0; i < count; i++)pvalue[i] = i + 1;for (int i = 0; i < ccount; i++)//打乱ccount指定的次数，每次取第一个值存入数组{random_shuffle(pvalue.begin(), pvalue.end());value.push_back(pvalue[0]);}return value;}

c++ Primer Plus（习题16.8)

//两个朋友认识的人的名字，用容器存储//合并两个人中相同的元素，保存到第三个容器中//考虑采用set关联容器#include<iostream>#include<string>#include<set>#include<algorithm>#include<iterator>//迭代器的头文件int main(){using namespace std;ostream_iterator<string, char>out(cout, " ");//输出迭代器string Mat[5] = { "Joly","Jack","Zoe","Jay,Zou","X" };//直接用这个来初始化了string Pat[4] = { "Joly","Emil","X","Lai Mei" };set<string>A(Mat, Mat + 5);//第一个容器,set容器自动排序，大家都知道cout << "Mat's friends:\n";copy(A.begin(), A.end(), out);//STL函数，复制到输出流迭代器cout << endl;//说白了，就是显示容器内容set<string>B(Pat, Pat + 4);cout << "Pat's friends:\n";copy(B.begin(), B.end(), out);cout << endl;set<string>C;set_union(A.begin(), A.end(), B.begin(), B.end(), insert_iterator<set<string>>(C, C.begin()));//AB集合，用了一个插入迭代器cout << "Friends they have:\n";copy(C.begin(), C.end(), out);cout << endl;return 0;}

c++ Primer Plus（习题16.9)

//这是作者的一个假设，在我们生活中也有很多这样的假设//他的思路是在数组中排序元素，然后复制到链表中（因为链表排序是在很麻烦）//借用中间容器实现排序功能的实现，下面就是测试时间#include<iostream>#include<vector>#include<list>#include<algorithm>#include<iterator>#include<ctime>//提供时间函数const int Num=1000000;//这个要足够大void outint(int n) { std::cout << n << " "; }int main(){using namespace std;vector<int>vi0(Num);//指定个数的初始化for (int i=0; i < Num; i++)vi0[i]=rand()%100 + 1;cout << "Hello,this program set to accumulate time between STL sort method ""for vector object,and list sort methods.\n";cout << "Number of elements is " << Num << endl;vector<int>vi;vi = vi0;//调用vector的赋值运算符list<int>li(Num);//指定个数的初始化copy(vi0.begin(), vi0.end(), li.begin());//不同容器之间的数据复制//计算三种方法的时间，方法一，使用使用STL算法对vi进行排序clock_t start = clock();sort(vi.begin(), vi.end());clock_t end = clock();cout << "Frist method,using STL sort time " << (double)(end - start) / CLOCKS_PER_SEC << " s.\n";//第二次测试clock_t start_2= clock();li.sort();clock_t end_2= clock();cout << "Second method,using list sort time " << (double)(end_2 - start_2) / CLOCKS_PER_SEC << " s.\n";//第三次测试copy(vi0.begin(), vi0.end(), li.begin());//重置li链表clock_t start_3 = clock();copy(li.begin(), li.end(), vi.begin());//把list的值复制到vi容器sort(vi.begin(), vi.end());//排序copy(vi.begin(), vi.end(), li.begin());clock_t end_3 = clock();cout << "Third method,using other sort time " << (double)(end_3 - start_3) / CLOCKS_PER_SEC << " s.\n";cout << "Now,you can see,\nwhen list container count become big,sortting them is too long.""\nSo,make right choice to compelete a function.\n";return 0;}

c++ Primer Plus（习题16.10)

//又是修改程序的题目，这最后的习题涉及到智能指针//然后我们要做的就是满足客户的额要求,升级我们的程序//不知道加了哪个头文件导致cout不明确//这题的思路是书上的方案，如果自己做的话可以想排序字符串那样//只使用指针数组排序，对指针进行排序#include<iostream>#include<string>#include<vector>#include<algorithm>//提供一些STL方法#include<memory>//智能指针头文件struct Review//结构是一种默认为公有的类{std::string title;int rating;double price;//增加的成员，书价格};using namespace std;//书上也是按引用传递指针的意义非凡，其实不还是指针，没设呢么区别bool operator<(shared_ptr<Review>r1, shared_ptr<Review>r2);//按字母排序的bool woreThan(shared_ptr<Review>r1, shared_ptr<Review>r2);//评分排序的bool expensivethen(shared_ptr<Review>r1, shared_ptr<Review>r2);//价格排序的bool FillReview(Review*rr);void ShowReview(shared_ptr<Review>rr);//有点特别，书上的用法void Showmenu();int main(){Review temp;vector<shared_ptr<Review>>pr;while (FillReview(&temp))pr.push_back(shared_ptr<Review>(new Review(temp)));//没认真看书，这个初始化想了好久好久vector<shared_ptr<Review>>tem(pr);//用vector自带的初始化,是一个按名称排序的vectorsort(tem.begin(), tem.end());//创建按指针排序的<运算符，全排序//按评分排序的vector<shared_ptr<Review>>tem2(pr);sort(tem2.begin(), tem2.end(), woreThan);//调用函数进行排序，完整弱排序//按价格排序vector<shared_ptr<Review>>tem3(pr);sort(tem3.begin(), tem3.end(), expensivethen);if (pr.size() > 0){std::cout<< "Thank you,You entered the following "<< pr.size() << " ratings.\n";Showmenu();char choose;cin >> choose;while (choose != 'q'){switch (choose){//天真的我竟然在后面加&这个case 'a':for_each(pr.begin(),pr.end(), ShowReview); break;case'b': for_each(tem.begin(),tem.end(), ShowReview); break;case'c':for_each(tem2.begin(), tem2.end(), ShowReview); break;case'd':for_each(tem2.rbegin(), tem2.rend(), ShowReview); break;case 'e':for_each(tem3.begin(), tem3.end(), ShowReview); break;case'f':for_each(tem3.rbegin(), tem3.rend(), ShowReview); break;case 'q':break;default: std::cout << "Error choose,choose again:\n";break;}Showmenu();cin >> choose;}}elsestd::cout << "No data!\n";std::cout << "Bye!\n";return 0;}bool operator<(shared_ptr<Review>r1, shared_ptr<Review>r2){if (r1->title < r2->title)return true;else if (r1->title == r2->title&&r1->rating < r2->rating)return true;//这里不想太麻烦，就选择评分为优先排序项目elsereturn false;}bool woreThan(shared_ptr<Review>r1, shared_ptr<Review>r2)  //按评分升序{if (r1->rating<r2->rating)return true;elsereturn false;}bool expensivethen(shared_ptr<Review>r1, shared_ptr<Review>r2) //按价格升序{if (r1->price < r2->price)return true;elsereturn false;}bool FillReview(Review*rr){std::cout << "Enter book title(quit to quit): ";std::getline(std::cin, rr->title);if (rr->title == "quit")return false;std::cout << "Enter book rating: ";std::cin >> rr->rating;if (!std::cin)return false;//检查错误输入std::cout << "Enter book price(unit:yuan): ";std::cin >> rr->price;if (!std::cin)return false;while (std::cin.get() != '\n')continue;return true;}void ShowReview(shared_ptr<Review>rr){std::cout << rr->title<< "\t\t\t\t\t" << rr->rating << "\t $ " << rr->price << "\tyuan.\n";}void Showmenu(){std::cout << "Make a choose to display them: \n""a) Display by original order.            b) Display by alphabetic order.\n""c) Display by rating ascending order.     d) Display by rating descending order.\n""e) Display by price ascending order.      f) Display by price descending order.\n""q) quit.\n";}