C++Primer Plus（第六版）第六章编程练习

第六第七第九题没做，和其他练习大同小异

#include<iostream>
#include<fstream>
#include<cctype>

#define strsize 20
using namespace std;

struct bop
{
    char fullname[strsize];
    char title[strsize];
    char bopname[strsize];
    int preference;
};
int main()
{
    /*cout << "No.1" <<endl;
    char ch;
    while((ch = cin.get())!= '@')
    {
        if(isalpha(ch) && islower(ch))
        {ch = toupper(ch);
        cout << ch;}
        else if(isalpha(ch) && isupper(ch))
            {ch = tolower(ch);
            cout << ch;}
    }
    cout << "No.2" << endl;
    double donation, average = 0;
    double ar[10];
    int i = 0;
    int j = 0;
    int n = 0;
    cin >> donation;
    while(cin.good())
    {
        ar[i] = donation;
        i++;
        if(i == 10)
            break;
        cin >> donation;
    }
    for (j = 0 ; j < i ; j++)
    {
        average += ar[j];
    }
    average = average / i;
    for (j = 0 ; j < i ; j++)
    {
        if(ar[j] > average)
        {
            n++;
        }
    }
    cout << "Average :"<< average <<endl;
    cout << "Bigger than Ave:"<< n <<endl;
    cout << "No.3"<< endl;
    cout << "Please enter one of the following choices:"<<endl;
    cout << "c) carnivore \t p) pianist \nt) tree \t g) game"<<endl;
    cout << "Please enter a c, p, t, or g:";
    char flag;
    cin >> flag;
    while(flag != 'c' && flag != 'p' && flag != 't' && flag != 'g')
    {
         cout << "Please enter a c, p, t, or g:";
         cin >> flag;
    }
    switch (flag)
    {
        case 'c': cout << "Tiger is a carnivore"<<endl;
        break;
        case 'p': cout << "Chopin is an pianist"<<endl;
        break;
        case 't': cout << "Maple is a tree"<<endl;
        break;
        case 'g': cout << "No man sky is a game"<< endl;
        break;
    }
    cout << "No.4"<<endl;
    bop member[3] = {
        {"Emma Watson", "Hige level" ,"Dora",0 },
        {"Edward Nowton" , "Middle level", "Pigg",1},
        {
            "New Yorker" , "low level" , "Dude" ,2
        }
        };
    cout << "Benavolent Order of Programmers Report:"<<endl;
    cout << "a. display by name \t b.display by title \nc. display by bopname \t d. display by preference  \nq. quit"<<endl;
    char flag;
    cout << "Enter your choice:";
    while(1)
    {
        cin >> flag;
    switch (flag)
    {
    case 'a':
        for (int i = 0; i<3 ;i++)
        {
            cout << member[i].fullname<<endl;
        }
        break;
    case 'b':
        for (int i = 0; i<3 ;i++)
            cout << member[i].title<<endl;
        break;
    case 'c':
        for (int i = 0; i<3 ;i++)
            cout << member[i].bopname<<endl;
        break;
    case 'q':
        cout << "bye";
        break;
    }
    if(flag == 'q')
        break;
    }

    cout << "No.5"<<endl;
    double income,tax;
    cin >> income;
    cout << fixed;
    cout.setf(ios_base::showpoint);
    cout.precision(2);
    while(cin.good() && income > 0)
    {
       if(income < 5000)
            cout << "tax = 0"<<endl;
       else if(income > 5000&& income < 15000)
       {
           tax = 5000 * 0 + (income - 5000) * 0.1;
           cout << "tax = "<<tax<<endl;
       }
       else if(income > 15000&& income <= 35000)
       {
           tax = 5000 * 0 + 10000 * 0.1+(income - 15000) * 0.15;
           cout << "tax = "<<tax<<endl;
       }
       else if(income > 35000){
           tax = 5000 * 0 + 10000 * 0.1+20000 * 0.15+(income - 35000) * 0.15;
           cout << "tax = "<<tax<<endl;
           }
        cin >> income;
    }
    cout << "No.8"<<endl;
    ifstream infile;
    infile.open("carinfo.txt");
    int i = 0;
    infile.get();
    if(!infile.is_open())
    {
        cout << "opening file has been failed"<<endl;
    }
    while(infile.good())
    {
        i++;
        infile.get();
    }
    cout << i << " chars in this file"<<endl;
    */

    return 0;
}