实验五

#include <iostream> #include <vector> #include <string> using namespace std; // 函数声明 void output1(vector<string> &); void output2(vector<string> &); int main() { vector<string>likes, dislikes; // 创建vector<string>对象likes和dislikes likes.push_back("favourite book "); likes.push_back("favourite music"); likes.push_back("favourite film"); likes.push_back("favourite paintings"); likes.push_back("favourite anime"); likes.push_back("favourite sport"); likes.push_back("favourite sportsman"); dislikes.push_back("dislike book "); dislikes.push_back("dislike music"); dislikes.push_back("dislike film"); dislikes.push_back("dislike paintings"); dislikes.push_back("dislike anime"); dislikes.push_back("dislike sport"); dislikes.push_back("dislike sportsman"); // 为vector<string>数组对象likes添加元素值 ( favorite book, music, film, paintings,anime,sport,sportsman,etc) cout << "-----I like these-----" << endl; output1(likes); // 调用子函数输出vector<string>数组对象likes的元素值 // 为vector<string>数组对象dislikes添加元素值 cout << "-----I dislike these-----" << endl; output1(dislikes); // 调用子函数输出vector<string>数组对象dislikes的元素值 // 交换vector<string>对象likes和dislikes的元素值 likes.swap(dislikes); cout << "-----I likes these-----" << endl; // 调用子函数输出vector<string>数组对象likes的元素值 output2(likes); cout << "-----I dislikes these-----" << endl; // 调用子函数输出vector<string>数组对象dislikes的元素值 output2(dislikes); return 0; } // 函数实现 // 以下标方式输出vector<string>数组对象v的元素值 void output1(vector<string> &v) { int i; for(i=0;i<v.size();i++){cout<<v[i]<<endl;} cout<<endl; } // 函数实现 // 以迭代器方式输出vector<string>数组对象v的元素值 void output2(vector<string> &v) { vector<string>::iterator it; for(it=v.begin();it!=v.end();++it){cout<<*it<<endl;} cout<<endl; }

 

6-17

指针应该先有地址才可以被赋值，所以改为如下：

#include<iostream> using namespace std; int main() { int i,*p=&i; i=9; cout<<"The value at p:"<<*p; return 0; }

 6-18

在分配内存使用完后要释放，

#include<iostream> using namespace std; int fn1(); int main() { int a=fn1(); cout<<"the value of a is:"<<a; } int fn1(){ int *p=new int (5); return *p; delete p; }

期中：

#include<iostream> #include<cstdlib> using namespace std; class Dice{ public: Dice(int n); int cast(); private: int sides; }; Dice::Dice(int n):sides(n){ } int Dice::cast(){ return rand()%sides+1; } int main() { int amount,number; cout<<"输入班级的人数与学号："; cin>>amount>>number; Dice A(amount); int i,j; double k; for(i=1;i<=500;i++){ if(A.cast()==amount) j++; } k=(double)j/500; cout<<"选到"<<number<<"学号的概率是："<<k<<endl; return 0; }

 

 

 

3

book。cpp

#include "book.h" #include <iostream> #include <string> using namespace std; // 构造函数 Book::Book(string isbnX,string titleX,float priceX):isbn(isbnX),title(titleX),price(priceX){ } // 打印图书信息 void Book::print(){ cout<<"出版编号："<<isbn<<endl; cout<<"书名:"<<title<<endl; cout<<"定价："<<price<<endl; }

book.h

#ifndef BOOK_H #define BOOK_H #include <string> using std::string; class Book { public: Book(string isbnX, string titleX, float priceX); //构造函数 void print(); // 打印图书信息 private: string isbn; string title; float price; }; #endif

main.cpp

#include "book.h" #include <vector> #include <iostream> using namespace std; int main() { // 定义一个vector<Book>类对象 vector<Book> books; string isbn, title; float price; do{ cout<<"输入图书的出版编号，书名，定价：(输出请输入价格为0)"; cin>>isbn>>title>>price; Book x(isbn,title,price); books.push_back(x); }while(price!=0); // 录入图书信息，构造图书对象，并添加到前面定义的vector<Book>类对象中 // 循环录入，直到按下Ctrl+Z时为止 (也可以自行定义录入结束方式） // 输出入库所有图书信息 int i; for(i=0;i<books.size()-1;i++){ books[i].print(); } return 0; }

转载于:https://www.cnblogs.com/a18851962010/p/9078725.html