C++程序设计（第3版）谭浩强 第7章 习题
1.定义一个结构体变量（包括年、月、日），编写程序，要求输入年、月、日，程序能计算并输出该日在本年中是第几天。注意闰年问题。
【解】
#include
using namespace std;
struct
{
int year; //结构体变量date中的成员对应于输入的年、月、日
int month;
int day;
}date;
int main()
{
int days; //days为天数
cout << "input year,month,day:";
cin >> date.year >> date.month >> date.day;
switch (date.month)
{
case 1: days = date.day; break;
case 2: days = date.day + 31; break;
case 3: days = date.day + 59; break;
case 4: days = date.day + 90; break;
case 5: days = date.day + 120; break;
case 6: days = date.day + 151; break;
case 7: days = date.day + 181; break;
case 8: days = date.day + 212; break;
case 9: days = date.day + 243; break;
case 10: days = date.day + 273; break;
case 11: days = date.day + 304; break;
case 12: days = date.day + 334; break;
}
if (((date.year % 4 == 0 && date.year % 100 != 0) || date.year % 400 == 0) && date.month >= 3)
days += 1;
cout << date.month << "/" << date.day << " is the " << days << "th day in " << date.year << "." << endl;
return 0;
}
//（2）程序二
#include
using namespace std;
struct
{
int year;
int month;
int day;
}date;
int main()
{
int i, days;
int day_tab[13] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 };
cout << "input year,month,day:";
cin >> date.year >> date.month >> date.day;
days = 0;
for (i = 1; i < date.month; i++)
days += day_tab[i];
days += date.day;
if ((date.year % 4 == 0 && date.year % 100 != 0 || date.year % 400 == 0) && date.month >= 3)
days += 1;
cout << date.month << "/" << date.day << " is the " << days << "th day in " << date.year << "." << endl;
return 0;
} 运行结果：
//① input year, month, day:2005 10 1↙
//10 / 1 is the 274th day in 2005.
//② input year, month, day : 2008 10 1↙
//10 / 1 is the 275th day in 2008
2.编写一个函数days，实现上面的计算。由主函数将年、月、日传递给函数days，计算出该日在本年中是第几天并将结果传回主函数输出。
【解】
#include
using namespace std;
struct y_m_d
{
int year;
int month;
int day;
};
int main()
{
y_m_d date;
int days(int, int, int); //对days函数的声明
int day_sum;
cout << "input year,month,day:";
cin >> date.year >> date.month >> date.day;
day_sum = days(date.year, date.month, date.day);
cout << date.month << "/" << date.day << " is the " << day_sum << "th day in " << date.year << endl;
return 0;
}
int days(int year, int month, int day) //定义days函数
{
int day_sum, i;
int day_tab[13] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 };
day_sum = 0;
for (i = 1; i < month; i++)
day_sum += day_tab[i];
day_sum += day;
if ((year % 4 == 0 && year % 100 != 0 || year % 4 == 0) && month >= 3)
day_sum += 1;
return(day_sum);
} 运行结果：
//input year, month, day:2005, 7, 1↙
//10 / 1 is the 182th day in 2005.
3.编写一个函数print，打印一个学生的成绩数组，该数组中有５个学生的数据，每个学生的数据包括num(学号)、name(姓名)、score[3](3门课的成绩)。用主函数输入这些数据，用print函数输出这些数据。
【解】
#include
#include
using namespace std;
const int n = 5;
struct student
{
char num[6];
char name[8];
int score[4];
}stu[n];
int main()
{
void print(student stu[]);
int i, j;
for (i = 0; i < n; i++)
{
cout << "input scores of student " << i + 1 << ":" << endl;
cout << "NO.: ";
cin >> stu[i].num;
cout << "name: ";
cin >> stu[i].name;
for (j = 0; j < 3; j++)
{
cout << "score " << j + 1 << ":";
cin >> stu[i].score[j];
}
cout << endl;
}
print(stu);
return 0;
}
void print(student stu[])
{
int i, j;
cout << " NO. name score1 score2 score3" << endl;
for (i = 0; i < n; i++)
{
cout << stu[i].num << " " << setw(10) << stu[i].name << " ";
for (j = 0; j < 3; j++)
cout << setw(3) << stu[i].score[j] << " ";
cout << endl;
}
} 运行结果：
//input scores of student 1:
//NO. : 101↙
//NAME : Li↙
//score 1 : 90↙
//score 2 : 79↙
//score 3 : 89↙
//
//input scores of student 2 :
//NO. : 102↙
//NAME : Ma↙
//score 1 : 97↙
//score 2 : 90↙
//score 3 : 68↙
//
//input scores of student 3 :
//NO. : 103↙
//NAME : Wang↙
//score 1 : 77↙
//score 2 : 70↙
//score 3 : 78↙
//
//input scores of student 4 :
//NO. : 104↙
//NAME : Fun↙
//score 1 : 67↙
//score 2 : 89↙
//score 3 : 56↙
//
//input scores of student 5 :
//NO. : 105↙
//NAME : Xue↙
//score 1 : 87↙
//score 2 : 65↙
//score 3 : 69↙
//
//NO.name score1 score2 score3
//101 Li 90 79 89
//102 Ma 97 90 68
//103 Wang 77 70 78
//104 Fun 67 89 56
//105 Xue 87 65 69
4.在第3题的基础上，编写一个函数input，用来输入５个学生的数据。
【解】
#include
#include
using namespace std;
const int n = 5;
struct student
{
char num[6];
char name[8];
int score[4];
}stu[n];
int main()
{
void input(student stu[]);
void print(student stu[]);
input(stu);
print(stu);
return 0;
}
void input(student stu[])
{
int i, j;
for (i = 0; i < n; i++)
{
cout << "input scores of student " << i + 1 << ":" << endl;
cout << "NO.: ";
cin >> stu[i].num;
cout << "name: ";
cin >> stu[i].name;
for (j = 0; j < 3; j++)
{
cout << "score " << j + 1 << ":";
cin >> stu[i].score[j];
}
}
}
void print(student stu[])
{
int i, j;
cout << " NO. name score1 score2 score3" << endl;
for (i = 0; i < n; i++)
{
cout << stu[i].num << " " << setw(10) << stu[i].name << " ";
for (j = 0; j < 3; j++)
cout << setw(3) << stu[i].score[j] << " ";
cout << endl;
}
} 5.有10个学生，每个学生的数据包括学号、姓名、3门课的成绩，从键盘输入10个学生数据，要求打印出3门课总平均成绩，以及最高分的学生的数据（包括学号、姓名、3门课成绩、平均分数）。
【解】
#include
#include
using namespace std;
const int n = 3;
struct student
{
char num[6];
char name[8];
int score[4];
float avr;
} stu[n];
int main()
{
int i, j, max, maxi, sum;
float average;
for (i = 0; i < n; i++)
{
cout << "input scores of student " << i + 1 << endl;
cout << "NO.:";
cin >> stu[i].num;
cout << "name:";
cin >> stu[i].name;
for (j = 0; j < 3; j++)
{
cout << "score " << j + 1 << ":";
cin >> stu[i].score[j];
}
cout << endl;
}
average = 0;
max = 0;
maxi = 0;
for (i = 0; i < n; i++)
{
sum = 0;
for (j = 0; j < 3; j++)
sum += stu[i].score[j];
stu[i].avr = sum / 3.0;
average += stu[i].avr;
if (sum > max)
{
max = sum;
maxi = i;
}
}
average /= n;
cout << " NO. name score1 score2 score3 average" << endl;
for (i = 0; i < n; i++)
{
cout << setw(8) << stu[i].num << " " << setw(10) << stu[i].name << " ";
for (j = 0; j < 3; j++)
cout << setw(3) << stu[i].score[j] << " ";
cout << stu[i].avr << endl;
}
cout << "average=" << average << endl;
cout << "The highest score is :" << stu[maxi].name << ", score total:" << max << endl;
return 0;
} 运行结果：
//input scores of student 1:
//NO. : 101↙
//name : Wang↙
//score1 : 93↙
//score2 : 89↙
//score3 : 87↙
//
//input scores of student 2 :
//NO. : 102↙
//name : Li↙
//score1 : 85↙
//score2 : 80↙
//score3 : 78↙
//
//input scores of student 3 :
//NO. : 103↙
//name : Zhao↙
//score1 : 65↙
//score2 : 70↙
//score3 : 59↙
//
//input scores of student 4 :
//NO. : 104↙
//name : Ma↙
//score1 : 77↙
//score2 : 70↙
//score3 : 83↙
//
//input scores of student 5 :
//NO. : 105↙
//name : Han↙
//score1 : 70↙
//score2 : 67↙
//score3 : 60↙
//
//input scores of student 6 :
//NO. : 106↙
//name : Zhang↙
//score1 : 99↙
//score2 : 97↙
//score3 : 95↙
//
//input scores of student 7 :
//NO. : 107↙
//name : Zhou↙
//score1 : 88↙
//score2 : 89↙
//score3 : 88↙
//
//input scores of student 8 :
//NO. : 108↙
//name : Chen↙
//score1 : 87↙
//score2 : 88↙
//score3 : 85↙
//
//input scores of student 9 :
//NO. : 109↙
//name : Yang↙
//score1 : 72↙
//score2 : 70↙
//score3 : 69↙
//
//input scores of student 10 :
//NO. : 110↙
//name : Liu↙
//score1 : 78↙
//score2 : 80↙
//score3 : 83↙
//
//NO.Name score1 score2 score3 average
//101 Wang 93 89 87 89.67
//102 Li 85 80 78 81.00
//103 Zhao 65 70 59 64.67
//104 Ma 77 70 83 76.67
//105 Han 70 67 60 65.67
//106 Zhang 99 97 95 97.00
//107 Zhou 88 89 88 88.33
//108 Chen 87 88 85 86.67
//109 Yang 72 70 69 70.33
//110 Liu 78 80 83 80.33
//average = 80.03
//The highest score is : Zhang, score total : 291.
6.编写一个函数creat，用来建立一个动态链表。所谓建立动态链表是指在程序执行过程中从无到有地建立起一个链表，即一个一个地开辟结点和输入各结点数据，并建立起前后相连的关系。各结点的数据由键盘输入。
【解】
#include
using namespace std;
#define NULL 0
struct student
{long num;
float score;
struct student *next;
};
int main()
{student a,b,c,*head,*p;
a.num=10001; a.score=89.5;
b.num=10003; b.score=90;
c.num=10007; c.score=85; //对结点的num和score成员赋值
head=&a; //将结点a的起始地址赋给头指针head
a.next=&b; //将结点b的起始地址赋给a结点的next成员
b.next=&c; //将结点c的起始地址赋给b结点的next成员
c.next=NULL; //c结点的next成员不存放其他结点地址
p=head; //使p指针指向a结点
do
{cout<num<<" "<score<next; //使p指向下一结点
}while(p!=NULL); //输出完c结点后p的值为NULL
return 0;
}
#include
using namespace std;
#define NULL 0
struct student
{long num;
float score;
student *next;
};
//n为全局变量，本文件模块中各函数均可使用它
student *creat(void) //定义函数。此函数带回一个指向链表头的指针
{student *head;
student *p1,*p2;
int n=0;
p1=p2=new student; //开辟一个新单元，并使p1,p2指向它
cin>>p1->num>>p1->score;
head=NULL;
while(p1->num!=0)
{n=n+1;
if(n==1) head=p1;
else p2->next=p1;
p2=p1;
p1=new student;
cin>>p1->num>>p1->score;
}
p2->next=NULL;
return(head);
}
7.编写一个函数print，将第6题建立的链表中各结点的数据依次输出。
【解】
#include
using namespace std;
#define NULL 0
struct student
{
long num;
float score;
student *next;
};
int n;
student *del(student *head, long num)
{
student *p1, *p2;
if (head == NULL) //是空表
{
cout << "list null!" << endl; return(head);
}
p1 = head; //使p1指向第1个结点
while (num != p1->num && p1->next != NULL) //p1指向的不是所要找的结点且后面还有结点
{
p2 = p1; p1 = p1->next;
} //p1后移一个结点
if (num == p1->num) //找到了
{
if (p1 == head) head = p1->next; //若p1指向的是首结点，把第2个结点地址赋予head
else p2->next = p1->next; //否则将下一结点地址赋给前一结点地址
cout << "delete:" << num << endl;
n = n + 1;
}
else cout << "cannot find " << num; //找不到该结点
return(head);
} 8.编写一个函数del，用来删除动态链表中一个指定的结点(由实参指定某一学号，表示要删除该学生结点)。
【解】
#include
using namespace std;
#define NULL 0
struct student
{
long num;
float score;
student *next;
};
int n;
student *del(student *head, long num)
{
student *p1, *p2;
if (head == NULL) //是空表
{
cout << "list null!" << endl; return(head);
}
p1 = head; //使p1指向第一个结点
while (num != p1-> num && p1-> next != NULL) //p1指向的不是所要找的结点且后面还有结点
{
p2 = p1; p1 = p1-> next;
} //p1后移一个结点
if (num == p1-> num) //找到了
{
if (p1 == head) head = p1-> next; //若p1指向的是首结点，把第二个结点地址赋予head
else p2-> next = p1-> next; //否则将下一结点地址赋给前一结点地址
cout << "delete:" << num << endl;
n = n - 1;
}
else cout << "cannot find " << num; //找不到该结点
return(head);
} 运行结果：
9.编写一个函数insert，用来向动态链表插入一个结点。
【解】
student *insert(student *head, student *stud)
{
student *p0, *p1, *p2;
p1 = head; //使p1指向第1个结点
p0 = stud; //指向要插入的结点
if (head == NULL) //原来的链表是空表
{
head = p0; p0->next = NULL;
} //使p0指向的结点作为头结点
else
{
while ((p0->num > p1->num) && (p1->next != NULL))
{
p2 = p1; //使p2指向刚才p1指向的结点
p1 = p1->next;
} //p1后移1个结点
if (p0->num <= p1->num)
{
if (head == p1) head = p0; //插到原来第1个结点之前
else p2->next = p0; //插到p2指向的结点之后
p0->next = p1;
}
else
{
p1->next = p0; p0->next = NULL;
} //插到最后的结点之后
}
n = n + 1; //结点数加1
return (head);
}
运行结果：
10.将以上4个函数组成一个程序，由主程序先后调用这些函数，实现链表的建立、输出、删除和插入，在主程序中指定需要删除和插入的结点。
【解】
#include
using namespace std;
#define NULL 0
struct student
{
long num;
float score;
student *next;
};
int n;
int main()
{
student *creat(void);
student *del(student *, long);
student *insert(student *, student *);
void print(student *);
student *head, stu;
long del_num;
cout << "input records:" << endl;
head = creat(); //返回头指针
print(head); //输出全部结点
cout << endl << "input the deleted number:";
cin >> del_num; //输入要删除的学号
head = del(head, del_num); //删除后链表的头地址
print(head); //输出全部结点
cout << endl << "input the inserted record:"; //输入要插入的结点
cin >> stu.num >> stu.score;
head = insert(head, &stu); //返回地址
print(head); //输出全部结点
return 0;
}
//input records： （建立链表）
//10101 90↙
//10103 98↙
//10105 87↙
//0 0↙
//
//Now，These 3 records are：
//10101 90
//10103 98
//10105 87
//
//input the deleted number : 10103↙ （删除学号为10103的点）
//delete : 10003
//10101 90
//10105 87
//
//input the inserted record : 10102 95↙ （插入一个结点）
//
//Now, These 3 records are :
//10101 90
//10102 95
//10105 87
//
//input the inserted record : 10104 76↙ （再插入一个结点）
//Now, These 4 records are :
//10101 90
//10104 76
//10104 76
//10104 76
//修改后的整个程序如下：
#include
using namespace std;
#define NULL 0
struct student
{
long num;
float score;
student*next;
};
int n;
int main()
{
student *creat(void);
student *del(student *, long);
student *insert(student *, student *);
void print(student *);
student *head, *stu;
long del_num;
cout << "input records:" << endl;
head = creat(); //返回头指针
print(head); //输出全部结点
cout << endl << "input the deleted number:"; //请用户输入要删除的结点
cin >> del_num; //输入要删除的学号
while (del_num != 0) //当输入的学号为0时结束循环
{
head = del(head, del_num); //删除结点后的链表的头地址
print(head); //输出全部结点
cout << "input the deleted number:"; //请用户输入要删除的结点
cin >> del_num; //输入要删除的学号
}
cout << endl << "input the inserted record:"; //输入要插入的结点
stu = new student; //开辟一个新结点
cin >> stu->num >> stu->score;
while (stu->num != 0) //当输入的学号为0时结束循环
{
head = insert(head, stu); //返回链表的头地址, 赋给head
print(head); //输出全部结点
cout << endl << "input the inserted record:"; //请用户输入要插入的结点
stu = new student; //开辟一个新结点
cin >> stu->num >> stu->score; //输入插入结点的数据
}
return 0;
}
student *creat(void) //建立链表的函数
{
student *head;
student *p1, *p2;
n = 0;
p1 = p2 = new student; //开辟一个新单元, 并使p1,p2指向它
cin >> p1->num >> p1->score;
head = NULL;
while (p1->num != 0)
{
n = n + 1;
if (n == 1) head = p1;
else p2->next = p1;
p2 = p1;
p1 = new student;
cin >> p1->num >> p1->score;
}
p2->next = NULL;
return(head);
}
student *del(student *head, long num) //删除结点的函数
{
student *p1, *p2;
if (head == NULL) //是空表
{
cout << "list null!" << endl; return(head);
}
p1 = head; //使p1指向第一个结点
while (num != p1->num && p1->next != NULL) //p1指向的不是所要找的结点且后面还有结点
{
p2 = p1; p1 = p1->next;
} //p1后移一个结点
if (num == p1->num) //找到了
{
if (p1 == head) head = p1->next; //若p1指向的是首结点, 把第二个结点地址赋予head
else p2->next = p1->next; //否则将下一结点地址赋给前一结点地址
cout << "delete:" << num << endl;
n = n - 1;
}
else cout << "cannot find " << num; //找不到该结点
return(head);
}
student *insert(student *head, student *stud) //插入结点的函数
{
student *p0, *p1, *p2;
p1 = head; //使p1指向第一个结点
p0 = stud; //指向要插入的结点
if (head == NULL) //原来的链表是空表
{
head = p0; p0->next = NULL;
} //使p0指向的结点作为头结点
else
{
while ((p0->num > p1->num) && (p1->next != NULL))
{
p2 = p1; //使p2指向刚才p1指向的结点
p1 = p1->next;
} //p1后移一个结点
if (p0->num <= p1->num)
{
if (head == p1) head = p0; //插到原来第一个结点之前
else p2->next = p0; //插到p2指向的结点之后
p0->next = p1;
}
else
{
p1->next = p0; p0->next = NULL;
} //插到最后的结点之后
}
n = n + 1; //结点数加１
return(head);
}
void print(student *head) //输出链表的函数
{
student *p;
cout << "Now，These " << n << " records are：" << endl;
p = head;
if (head != NULL)
do
{
cout << p->num << " " << p->score << endl;
p = p->next;
} while (p != NULL);
}
//input records： （建立链表）
//10101 90↙
//10103 98↙
//10105 87↙
//0 0↙
//
//Now, These 3 records are :
//10101 90
//10103 98
//10105 87
//
//input the deleted number : 10103↙ （删除学号为10103的点）
//delete : 10103
//10101 90
//10105 87
//input the deleted number : 0↙ （输入的学号为0, 结束删除操作）
//
//input the inserted record : 10102 95↙ （插入一个结点）
//
//Now, These 3 records are :
//10101 90
//10102 95
//10105 87
//
//input the inserted record : 10104 76↙ （再插入一个结点）
//Now, These 4 records are：
//10101 90
//10102 95
//10104 76
//10105 87
//input the inserted record : 0 0↙ （输入的学号为0, 结束插入操作） 11.医院内科有A,B,C,D,E,F,G共7位医生，每人在一周内要值一次夜班，排班的要求是:
(1) A医生值班日比C医生晚1天；
(2) D医生值班日比E医生晚两天；
(3) B医生值班日比G医生早3天；
(4) F医生值班日在B医生和C医生值班日之间，且在星期四。
请编写程序，输出每位医生的值班日。值班日以Sunday, Monday, Tuesday, Wednesday, Thurday， Friday, Saturday分别表示星期日到星期六(提示: 用枚举变量)。
【解】
#include
using namespace std;
int main()
{
enum weekday { sun, mon, tue, wed, thu, fri, sat }; //声明枚举类型weekday
enum weekday day; //定义枚举变量day
int a, b, c, d, e, f, g, loop; //定义整型变量a,b,c,d,e,f,g,loop
char ch = 'A'; //定义字符变量c, 以便输出字符A,B,C,D,E,F,G
f = thu; //按题意F医生星期四值班
for (a = sun; a <= sat; a++) //需要逐个检查A医生星期几值班符合条件
if (a != f) // A医生值班日不应与F医生相同
for (b = sun; b <= sat; b++) //逐个检查B医生星期几值班符合条件
if ((a != b) && (f > b)) //B医生值班日不应与A医生相同, 且F在B之后
for (c = sun; c <= sat; c++) //逐个检查C医生星期几值班符合条件
if ((c != a) && (c != b) && (c != f) && (a == c + 1) && (f < c))
//C医生值班日不应与A,B,F医生相同, 且A比C晚一天
for (d = sun; d <= sat; d++) //逐个检查D医生星期几值班符合条件
if ((d != a) && (d != b) && (d != c) && (d != f) && (c == d + 3))
//D医生值班日不应与A,B,C,F医生相同, 且C在D之后3天
for (e = sun; e <= sat; e++) //逐个检查E医生星期几值班符合条件
if ((e != a) && (e != b) && (e != c) && (e != d) && (e != f) && (d == e + 2))
//E值班不应与A,B,C,D,F相同, 且E在D前2天
for (g = sun; g <= sat; g++) //逐个检查G医生条件
if ((g != a) && (g != b) && (g != c) && (g != d) && (g != e)
&& (g != f) && (g == b + 2))
//G值班不应与A,B,C,D,E,F相同, 且G在B后2天
//符合以上条件时才能继续执行下面的工作
for (loop = 0; loop < 7; loop++)
{
cout << "Doctor " << char(ch + loop) << ": ";
switch (loop + 1)
{
case 1: day = weekday(a); break;
//将a强制转换为weekday类型, 是A医生的值班日
case 2: day = weekday(b); break; //是B医生的值班日
case 3: day = weekday(c); break; //是C医生的值班日
case 4: day = weekday(d); break; //是D医生的值班日
case 5: day = weekday(e); break; //是E医生的值班日
case 6: day = weekday(f); break; //是F医生的值班日
case 7: day = weekday(g); //是G医生的值班日
}
switch (day) //以英文单词形式输出星期几
{
case sun: cout << "Sunday" << endl; break;
case mon: cout << "Monday" << endl; break;
case tue: cout << "Tuesday" << endl; break;
case wed: cout << "Wednesday" << endl; break;
case thu: cout << "Thursday" << endl; break;
case fri: cout << "Friday" << endl; break;
case sat: cout << "Saturday" << endl;
}
}
return 0;
}
运行结果：
//Doctor A : Saturday
//Doctor B : Monday
//Doctor C : Friday
//Doctor D : Tuesday
//Doctor E : Sunday
//Doctor F : Thursday
//Doctor G : Wednesday