C程序设计第七&九章

void main(){ //用指针实现赋值 Bookcard book[N], *b; float meanprice=0; for (b=book;b<book+N;b++){ gets(b->num); gets(b->name); gets(b->author); gets(b->publisher); scanf("%f",&b->price); meanprice=meanprice+b->price; getchar(); //fflush(stdin); } meanprice=meanprice/N; printf("%.2f",meanprice); }
9.2b.
void print(Bookcard *p){ Bookcard *b; for (b=p;b<p+N;b++){ puts(b->num); puts(b->name); puts(b->author); puts(b->publisher); printf("%.2f\n",b->price); printf("%d %d %d\n",b->date.year,b>date.month,b->date.day); } }
head B0 B1
r B2 p B3
9.4b.
void print(Bookcard *p){ Bookcard *b; b=p; while(b!=NULL){ puts(b->num); puts(b->name); puts(b->author); puts(b->publisher); b=b->next; } }
9.3b.
void sort(Bookcard *p){ Bookcard *b, *d; for (b=p;b<p+N-1;b++) for(d=b+1;d<p+N;d++) if (strcmp(b->num,d->num)>0 exchange(b,d); }
void main(){ Bookcard book[N]； read(book); sort(book); print(book); }
9.1b.
#include <stdio.h> #include <string.h> #define N 10 typedef struct Bookcard{ char num[10]; char name[30]; char author[30]; char publisher[60]; float price; } Bookcard;
ቤተ መጻሕፍቲ ባይዱ
9.4c.
Bookcard *delet(Bookcard *p){ Bookcard *b ,*pb; char num[10]; gets(num); pb=p; b=p; while(b!=NULL){ if (strcmp(num,b->num)==0){ if (b==p) p=b->next; else pb->next=b->next; return p; } pb=b; b=b->next; } }
7.2.程序输出结果（36）。
#include <stdio.h> #define f(x) x*x void main(){ int a=6,b=2,c; c=f(a)/f(b); //a*a/b*b printf("%d\n",c); }
7.3.程序输出结果（9.840000）。
#include <stdio.h> #define PR(a) printf(“%f",a) #define F(y) 3.84+y #define PRINT(a) PR(a); putchar('\n') void main(){ int x=2; PRINT(F(3)*x); }
void main(){ Bookcard book[N]; read(book); print(book); }
9.3a. 在第2题的基础上，增加一个按书号递增排序的排序函数sort，在 主函数中调用排序函数再输出图书信息。
void exchange(Bookcard *b, Bookcard *d){ Bookcard book1; strcpy(book1.num,b->num); strcpy(,b->name); strcpy(book1.author,b->author); strcpy(book1.publisher,b->publisher); book1.price=b->price; book1.date.year=b->date.year; book1.date.month=b->date.month; book1.date.day=b->date.day; strcpy(b->num,d->num); strcpy(b->name,d->name); strcpy(b->author,d->author); strcpy(b->publisher,d->publisher); b->price=d->price; b->date.year=d->date.year; b->date.month=d->date.month; b->date.day=d->date.day; strcpy(d->num,book1.num); strcpy(d->name,); strcpy(d->author,book1.author); strcpy(d->publisher,book1.publisher); d->price=book1.price; d->date.year=book1.date.year; d->date.month=book1.date.month; d->date.day=book1.date.day; } book1=*b; *b=*d; *d=book1;
9.2a. 在第1题定义的结构体类型中增加一个成员出版日期，该日期是一 个嵌套的结构类型变量，其中包括年、月、日；设计一个输入/输出图书 馆信息的函数read和print；并编写主函数定义一个10个元素的结构数组， 分别调用输入/输出函数输入和输出图书信息。
#include <stdio.h> #include <string.h> #define N 10 typedef struct Date{ int year; int month; int day; }Date; typedef struct Bookcard{ char num[10]; char name[30]; char author[30]; char publisher[60]; float price; Date date; } Bookcard; void read(Bookcard *p){ Bookcard *b; for (b=p;b<p+N;b++){ gets(b->num); gets(b->name); gets(b->author); gets(b->publisher); scanf("%f",&b->price); scanf("%d%d%d",&b->date.year,&b>date.month,&b->date.day); getchar(); //fflush(stdin); } }
第七章 预处理命令 第九章 结构体与共用体
7.1.宏调用实现变量a、b内容的交换。
#include <stdio.h> #define MYSWAP(z,x,y) {z=x;x=y;y=z;} void main(){ float a=5,b=16,c; MYSWAP(c,a,b); printf("%f %f %f\n",a,b,c); }
7.5.编写宏定义MyLpha(c)，以判定c是大写字母还是小写字母，当c是小 写字母时宏调用取值为1，当c是大写字母时宏调用取值为0。
#include <stdio.h> #define MyLpha(c) (c>=97)?1:0 void main(){ char c; scanf("%c",&c); if (MyLpha(c)) printf("%c\n",c-32); else printf("%c\n",c+32); }
7.4.swap(a,b)实现两个参数互换。
#include <stdio.h> #define swap(a,b) {a=a^b; b=b^a;a=a^b;} //异或，对a和b类型有限制 //#define swap(a,b) {a=a+b;b=a-b;a=a-b;} //求和，对a和b上界有限制 void main(){ int a, b; scanf("%d%d",&a,&b); swap(a,b); printf("%d %d\n",a,b); }
9.1a. 定义一个图书馆相关信息的结构体类型和结构体变量，其中包括 成员书号、书名、作者、出版社和价格；从键盘输入10本图书信息，计 算并输出这10本图书的平均价格。
#include <stdio.h> #include <string.h> #define N 10 typedef struct Bookcard{ char num[10]; char name[30]; char author[30]; char publisher[60]; float price; } Bookcard; void main(){ Bookcard book[N]; int i=0; float meanprice=0; for (i=0;i<N;i++){ scanf("%s",book[i].num); scanf("%s",book[i].name); scanf("%s",book[i].author); scanf("%s",book[i].publisher); scanf("%f",&book[i].price); meanprice=meanprice+book[i].price; } meanprice=meanprice/N; printf("%.2f",meanprice); }