C++ Primer Plus 学习笔记 第五章 编程练习

第一题

#include <iostream> using namespace std; int main() { cout<<"请输入两个整数，将计算两个整数之间（包括这两个整数）所有整数的和\n"; int first,twice,last=0; cin>>first>>twice; for (int i=first;i<=twice;i++) { last=last+i; } cout<<"和为："<<last<<endl; return 0; }

第二题

#include <iostream> #include <array> using namespace std; const int ArSize = 100; int main() { //array<int,n_elem> arr; array<long double,ArSize> factorials; factorials[1]=factorials[0]=1; for (int i=2;i<ArSize;i++) { factorials[i]=i*factorials[i-1]; } cout.setf(ios_base::fixed); for (int i=0;i<ArSize;i++) { cout<<i<<"!="<<factorials[i]<<endl; } return 0; }

第三题

#include <iostream> using namespace std; int main() { cout<<"请输入数字，将输出累计和，输入0停止\n"; int number,sum=0; do { cin>>number; sum=sum+number; }while(number!=0); cout<<"累计和为："<<sum<<endl; }

第四题

#include <iostream> using namespace std; const double simple_interest = 0.10;// const double compound_interest = 0.05; int main() { double Daphne,Cleo; int number=0; Daphne=Cleo=100; while(Daphne>=Cleo) { Daphne = Daphne+10; Cleo = Cleo+Cleo*compound_interest; number++; } cout<<"Daphne: "<<Daphne<<"美元"<<endl; cout<<"Cleo: "<<Cleo<<"美元"<<endl; cout<<number<<"年之后Cleo比Daphne多"<<endl; return 0; }

第五题

#include <iostream> using namespace std; const int month = 12; int main() { const char * Month[month]= { "January", "February", "March", "April", "May", "June", "July", "Aguest", "September", "October", "November", "December" }; int Sales[month]; int sum=0; cout<<"输入每个月的销量"<<endl; for (int i=0;i<12;i++) { cout<<Month[i]<<":"; cin>>Sales[i]; sum=sum+Sales[i]; } cout<<"今年的销量为："<<sum<<endl return 0; }

第六题

#include <iostream> using namespace std; const int month = 12; const int years = 3; int main() { const char * Month[month]= { "January", "February", "March", "April", "May", "June", "July", "Aguest", "September", "October", "November", "December" }; int Sales[years][month]; int annual[years]={0}; int sum=0; for (int i=0;i<years;i++) { cout<<"第"<<i+1<<"年\n"; cout<<"输入每个月的销量"<<endl; for (int j=0;j<month;j++) { cout<<Month[j]<<":"; cin>>Sales[i][j]; annual[i]=annual[i]+Sales[i][j]; } cout<<"第"<<i+1<<"年的销量是："<<annual[i]<<endl; sum=sum+annual[i]; } cout<<"3年的总销售量为："<<sum<<endl; return 0; }

第七题

/* 设计一个car结构，存储汽车信息，使用new来创建一个由相应数量的car结构组成的动态数组。输入每辆车的生产商和年份（交替读取数值和字符串）显示每个结构的内容。 */ #include <iostream> #include <cstring> #include <string> using namespace std; struct Car{ string producer;//生产商 int year;//生产年份 }; int main() { cout<<"How many cars do you wish to catalog?"; int num; cin>>num; Car *car=new Car [num]; for (int i=0;i<num;i++) { cout<<"Car #"<<i+1<<":"<<endl; cout<<"Please enter the made: "; cin.get(); getline(cin,car[i].producer);//数组名是指针，数组元素就相当于所指向的变量，所以用. cout<<"Please enter the year made: "; cin>>car[i].year; } cout<<"Here is your collection: \n"; for (int i=0;i<num;i++) { cout<<car[i].year<<" "<<car[i].producer<<endl; } delete [] car; return 0; }

第八题

/*编写一个程序，它使用一个char数组和循环来读取一个单词，直到用户输入done为止。随后指出用户输入了多少个单词。*/ #include <iostream> #include <cstring> using namespace std; const int ArSize = 10; int main() { cout<<"Enter words (to stop, type the word down)\n"; char words[ArSize]; int num=0; cin>>words; while (strcmp(words,"done")) { cin>>words; num++; } cout<<"\nYou entered a total of "<<num<<"words\n"; return 0; }

第九题

/*编写一个程序，它使用一个string和循环来读取一个单词，直到用户输入done为止。随后指出用户输入了多少个单词。*/ #include <iostream> #include <cstring> using namespace std; int main() { cout<<"Enter words (to stop, type the word down)\n"; string words; int num=0; cin>>words; while (words!="done") { cin>>words; num++; } cout<<"\nYou entered a total of "<<num<<" words\n"; return 0; }

第十题

/* 使用嵌套循环，要求用户输入一个值，指出要显示多少行。程序将显示相应行数的星号，第一行包括一个星号，第二行包括两个星号，在星号不够的情况下用.来凑 */ #include <iostream> using namespace std; int main() { cout << "enter number of rows: "; int num; cin >> num; int some = 1; while (some <= num) { for (int j = 0; j < num - some; j++) { cout << "."; } for (int i = 0; i < some; i++) //此循环用来输出*号 { cout << "*"; } some++; cout << endl; } return 0; }