c++ primer plus 习题答案(4)

p333.3

 1 #include<iostream>

 2 #include<cstdlib>

 3 #include<cstring>

 4 #include<string>

 5 using namespace std;

 6 

 7 class Golf{

 8 private:

 9     static const int Len = 40;

10     char fullname[Len];

11     int handicap;

12 public:

13     Golf(char name[Len], int bt);

14     void showgolf() const;

15 };

16 

17 void setgolf(char *name, int extent, int &bt){

18     cout << "enter a name\n";

19     cin.get(name, extent);

20     while (cin.get() != '\n')

21         continue;

22     cout << "enter a number\n";

23     cin >> bt;

24 }

25 

26 Golf::Golf(char name[Len], int bt){

27     strncpy(fullname, name, Len);

28     handicap = bt;

29 }

30 

31 void Golf::showgolf()const{

32     cout << "fullname is " << fullname << endl

33         << "handicap is " << handicap;

34 }

35 

36 int main(){

37     Golf one = Golf("asxc", 5);

38     int ct;

39     char name[40];

40     setgolf(name, 40, ct);

41     Golf two = Golf(name, ct);

42     one.showgolf();

43     cout << endl;

44     two.showgolf();

45 

46     system("pause");

47     return 0;

48 }

p333.4

 1 //头文件

 2 namespace SALES

 3 {

 4     class Sales{

 5     private:

 6         enum {QUARTERS=4};

 7         double sales[QUARTERS];

 8         double average, max, min;

 9     public:

10         Sales();

11         Sales(const double *ar, int n);

12         void showsales();

13     };

14 }

15 

16 //方法

17 #include<iostream>

18 #include"sales.h"

19 using namespace std;

20 

21 SALES::Sales::Sales(){

22     cout << "enter four number\n";

23     double sum = 0;

24     for (int i = 0; i < QUARTERS; i++){

25         cin >> sales[i];

26         sum += sales[i];

27     }

28     average = sum / QUARTERS;

29     max = sales[0];

30     min = sales[0];

31     for (int i = 1; i < QUARTERS; i++){

32         if (max < sales[i])

33             max = sales[i];

34         if (min>sales[i])

35             min = sales[i];

36     }

37 }

38 

39 SALES::Sales::Sales(const double *ar, int n){

40     double sum = 0;

41     for (int i = 0; i < n; i++){

42         sales[i] = ar[i];

43         sum += sales[i];

44     }

45     average = sum / QUARTERS;

46     max = sales[0];

47     min = sales[0];

48     for (int i = 1; i < QUARTERS; i++){

49         if (max < sales[i])

50             max = sales[i];

51         if (min>sales[i])

52             min = sales[i];

53     }

54 }

55 

56 void SALES::Sales::showsales(){

57     cout << "average is " << average << endl

58         << "max is " << max << endl

59         << "min is " << min;

60 }

61 

62 //驱动

63 #include<iostream>

64 #include"sales.h"

65 using namespace std;

66 

67 int main(){

68     using namespace SALES;

69     cout << "enter four number\n";

70     double ar[4];

71     for (int i = 0; i < 4; i++)

72         cin >> ar[i];

73     Sales market1(ar, 4);

74     market1.showsales();

75     Sales market2;

76     cout << endl;

77     market2.showsales();

78 

79     system("pause");

80     return 0;

81 }

p333.5

  1 //头文件：

  2 #ifndef _STACK_H_

  3 #define _STACK_H_ 

  4 

  5 struct customer{

  6     char fullname[35];

  7     double payment;

  8 };

  9 

 10 typedef customer Item;

 11 

 12 class Stack{

 13 private:

 14     enum{max=10};

 15     Item items[max];

 16     int top;

 17 public:

 18     Stack();

 19     bool isfull()const;

 20     bool isempty()const;

 21     void push(const Item &);

 22     bool pop(const Item &);

 23 };

 24 

 25 #endif

 26 

 27 //方法

 28 #include<iostream>

 29 #include"stack.h"

 30 using namespace std;

 31 

 32 Stack::Stack(){

 33     top = 0;

 34 }

 35 

 36 bool Stack::isfull()const{

 37     if (top == max)

 38         return true;

 39     else return false;

 40 }

 41 

 42 bool Stack::isempty()const{

 43     if (top == 0)

 44         return true;

 45     else return false;

 46 }

 47 

 48 void Stack::push(const Item &temp){

 49     if (isfull())

 50         cout << "the stack has already full\n";

 51     else items[top++] = temp;

 52 }

 53 

 54 bool Stack::pop(const Item &temp){

 55     if (isempty()){

 56         cout << "the stack has already empty\n";

 57         return false;

 58     }

 59     else {

 60         items[--top] = temp;

 61         return true;

 62     }

 63 }

 64 

 65 //驱动：

 66 #include<iostream>

 67 #include"stack.h"

 68 using namespace std;

 69 void get_customer(Item &);

 70 

 71 int main(){

 72     Item temp;

 73     Stack test;

 74     double payments=0;

 75     cout << "enter A to push, enter P to pop or"

 76         <<"enter Q to quit\n";

 77     char ch;

 78     while (cin >> ch && (ch != 'Q' && ch != 'q')){

 79         while (cin.get() != '\n')

 80             continue;

 81         switch (ch){

 82         case 'A':

 83         case 'a':

 84             get_customer(temp);

 85             test.push(temp);

 86             break;

 87         case 'P':

 88         case 'p':

 89             if (test.pop(temp))

 90                 payments += temp.payment;

 91             cout << "now total payments is " <<

 92                 payments << endl;

 93         default:

 94             cout << "please enter A/P or Q\n";

 95         }

 96         cout << "enter A to push, enter P to pop or"

 97             << "enter Q to quit\n";

 98     }

 99     system("pause");

100     return 0;    

101 }

102 

103 void get_customer(Item &temp){

104     cout << "enter a line\n";

105     cin.getline(temp.fullname, 35);

106     cout << "enter a number\n";

107     cin >> temp.payment;

108     cin.get();

109 }