浙江大学C颜晖原版C9

1、第九章 结构v结构v结构数组v结构指针v链表v位运算v自定义类型学号姓名性别出生地出生年出生月出生日数学物理 程序设计学号姓名性别出生地年 月 日 数学 物理 程序设计出生日期国家 省 市/县学习成绩结构：同一个数据项的若干成分构成的一个整体。例如：学生档案，每个学生有学号、姓名、性别、出生地、出生年月、学业成绩等。9.1 结构9.1.1 结构的定义struct student long int num; char name20; float score; ;定义一个结构类型： struct student9.1.2 结构变量的定义1、先定义结构类型，再定义变量struct student l

2、ong int num; char name20; float score; ;struct student stu1, stu2; num namescorestu1200011Zhang85stu2200012Li942、定义结构类型的同时定义变量struct student long int num; char name20; float score; stu1, stu2;3、不指定类型名，只定义变量struct long int num; char name20; float score; stu1, stu2;9.1.3 结构变量的初始化只有全局变量或静态变量才能初始化。stati

3、c struct student stu2=200012, “Li”, 94; num namescorestu2200012Li94 num namescorestu1200011Zhang85struct student long num; char name20; float score; stu1=200011, Zhang, 85;9.1.4 结构变量的使用1、结构类型变量的整体引用(1) 不能整体输入输出，但相同类型的变量可以互相赋值 printf(%ld%s%f, stu1); 非法 stu2=stu1; 合法(2) 可以引用结构体变量的地址 printf(%x, &st

4、u1); 输出stu1的首地址2、结构变量中分量的引用struct student long int num; char name20; float score; stu1, stu2;(1) 结构变量.分量 stu1.num = 9901; printf(%s, ); num namescorestu1200011Zhang85stu2200012Li94(2) 结构变量中的分量可以依据它的类型进行各种运算x = stu1.score;strcpy(, “Wang”);(3) 可以引用结构变量中的分量的地址 scanf(%ld, &stu1.num

5、);9.2 结构数组一个结构变量只能存放一个学生的资料。若班上有20个学生，需要用结构数组。即，数组中的每个元素都是结构类型。9.2.1 定义 struct student long int num; char name20; float score; stu20;stu0200011Zhang 85stu19200012Li90200029Zhao70stu19.2.2 初始化 struct student long int num; char name20; float score; stu20=200011,”Zhang”,85, 200012,”Li”,90;stu0200011Zha

6、ng 85stu19200012Li90200029Zhao70stu19.2.3 引用 struct student long int num; char name20; float score; stu20；stu0.scorestu0200011Zhang 85stu19200012Li90200029Zhao70stu1程序举例例1、输入某班30位学生的姓名及数学、英语成绩，计算并输出每位学生的平均分。struct student char name10; int math, eng; float aver; ;void main( ) struct

7、student s30; int i; for(i=0; i30; i+) scanf(%s%d%d, , &si.math, &si.eng); si.aver = (si.math+si.eng)/2.0 printf(%s%f, , si.aver); s0s29s1Zhang8085Li7790wang6078输入某班30位学生的姓名及数学、英语成绩，计算并输出每门课程的平均分。void main( ) struct student s30; int i; float aver_m=0, aver_e=0;例2 for(i=0; i30; i

8、+) scanf(%s%d%d, , &si.math, &si.eng); aver_m += si.math; aver_e += si.eng; printf(%f%f, aver_m/30, aver_e/30); 输入30位学生的姓名及数学、英语成绩，输出平均分最高的学生的姓名及其数学和英语成绩。struct student char name10; int math, eng; float aver; ;例3void main( ) struct student s30; int i, sub; for(i=0; i30; i+) scanf(%s%d

9、%d, , &si.math, &si.eng); si.aver = (si.math+si.eng)/2.0 sub=0; for( i=1; i ssub.aver ) sub = k; printf(%s%d%dn, , ssub.math, ssub.eng);9.3 结构指针9.3.1 定义struct student long int num; char name20; float score; ;struct student stu1, *ptr;ptr = &stu1; num namescorestu1200011Zh

10、ang85ptr9.3.2 结构指针的使用struct student stu1, *ptr = &stu1;stu1.num=200011; stu1.score=85; strcpy(,”Zhang”);通过指针 ptr 访问结构分量(1) *ptr (*ptr).num = 200011; (*ptr).score = 85; strcpy(*ptr).name,”Zhang”); num namescorestu1200011Zhang85ptr(2) - (*ptr).num = 200011; ptr-num = 200011; ptr-score = 8

11、5; strcpy(ptr-name,”Zhang”);当ptr = &stu1时stu1.num(*ptr).numptr-num 三者等价 num namescorestu1200011Zhang85ptrptr-num + 等价于 (ptr-num) + ptr-num 等价于 + (ptr-num)(+ ptr)-num num namescorestu1200011Zhang85ptr9.4 链表9.4.1结构的嵌套定义struct day int y; int m; int d;年 月 日成绩出生日期姓名学号struct student long int num; char

12、 name20; struct day birthday; float score; ymdscorebirthdaynamenumstruct day int y; int m; int d;struct student long int num; char name20; struct day birthday; float score; stu1, stu2;ymdscorebirthdaynamenum或：struct student long int num; char name20; struct int y, m, d; birthday; float score; stu1,

13、stu2;struct student long int num; char name20; struct int y, m, d; birthday; float score; stu1=9901, “Zhao”, 1980, 10,30, 80, stu2;stu2.birthday.y=1979;stu2.birthday.y=1;stu2.birthday.y=20;ymdscorebirthdaynamenum9.4.2 单向链表struct student long int num; float score; struct student *next;结构的递归定义head9901

14、 809902 909903 75 NULL1、动态内存分配函数(1) void *malloc(unsigned size)功能：在内存的动态存贮区中分配一块长度为size的连续空间。返回值：指针，存放被分配内存的起始地址。若未申请到空间，则返回 NULL( 0 )。 void *：指向任何类型的数据，在使用时，要进行强制类型转换。例如：(int *) malloc(sizeof(int)(struct student *) malloc(sizeof(struct student)(2) void free(void *ptr)功能：释放由malloc()申请的动态内存空间，ptr存放该空

15、间的首地址。返回值：无。p=(struct student *) malloc(sizeof(struct student);free(p);2、建立链表编写一个函数，要求用单向链表建立学生档案，从键盘输入数据，如果学号为0，输入结束，并返回链表的头指针。struct student long int num; float score; struct student *next;；struct student *head, *tail, *p;head=tail=NULL;struct student *head, *tail, *p;head=tail=NULL;size=sizeof(st

16、ruct student);p = (struct student *) malloc(size);pnum scorenextheadtailptailhead=tail=NULL;input num, scorewhile num!=0 p= (struct student *) malloc(sizeof(size) p-num=num, p-score=score, p-next=NULL y head=NULL n head=p tail-next=p tail=p input num, score # include stdio.hstruct student int num;fl

17、oat score;struct student *next;struct student *creat( );main( )struct student *head;head = creat( );struct student *creat() struct student *head, *tail, *p; float score; int num, size = sizeof(struct student); head = tail = NULL; scanf(%d %f, &num, &score); while (num) p = (struct student *)

18、malloc(size); p-num = num; p-score = score; p-next = NULL; if(head = NULL) head = p; else tail-next = p; tail = p; scanf(%d %f, &num, &score); return head; 3、遍历链表ptr-numptr-scorehead9901 809902 909903 75 NULLptrptrfor(ptr=head; ptr!=NULL; ptr=ptr-next) printf(“%ld, %f”, ptr-num, ptr-score);p

19、tr=ptr-next# include stdio.hstruct student int num;float score;struct student *next;struct student *creat( );void print(struct student *head)main( ) struct student *head;head = creat();print(head);void print(struct student *head) struct student *ptr; if(head = NULL) printf(n No listn); return; printf(n listn); for (ptr = head; ptr; ptr = ptr-next) printf( %d %fn, ptr-num, ptr-score);4、对链表的删除操作ptr2=ptr1-nextptr1-next=ptr2-nextheadptr1ptr2headptr1free(ptr2)ptr2=ptr1-nextptr24、对链表的插入操作s-next = ptr-nextptr-next = s先连后断headptrs9.5 位运算9.5.1 位运算符1、位逻辑运算符 按位取反(与!同级) 单目右结合& 按位与 按位异或