习题答案(35)

1、习题解答 2689101113第 1 章 . 第 2 章 . 第 3 章 . 第 4 章 . 第 5 章 . 第 6 章 . 第 7 章 . 第 8 章 . 第 9 章 . 第 10 章 第 11 章 第 12 章16习题解答第1章1.C 语言程序主要由预处理命令、函数、注释等组成。2.填空(1)分号(2) main(3) stdio.h3.源程序：#include main( ) printf( printf( printf(4. 源程序：“ *Hello World!n ”);“ *n”);); ”1.2.#include main( )*/*/int a, b, c; /* 定义变量 *

2、/ scanf(“%d ”, &a); /* 输入第一个整数 scanf(“%d ”, &b); /* 输入第二个整数 c=a-b; /* 计算差 */ printf( “%d-%d=%d ”,a,b,c); /* 输出结果 */5.#include (stdio.h) main( )/*改为 */int x , y , s ; x=10 y=20; s=x y ; printf(s = %dn , s ); /* 改为 printf( “s=%dn”,s); */*改为 x=10;*/第2章(1) c (2) a (3) b (4)b (5) a (6) d (7)c3.4.5.a5 b29

3、4 c4 d29 e9a.xH4yyH6 b XH4yyH3 C.XH4yyH4d. xH4yyH8e. xH4yyH9f. xH3yH6#inc-udeAsfdio.hv3ain()宀inf abc 八scanf(=%dwcrcaeb=CHa*b八prinff(=%d*wdHwcrabc=.6.3 b (2)b(3)d(4)a (5) b (6)amacbLs%.2f 齐 2f#inc-udeAsfdio.hv3ain()宀inf numynumNnumasum八 f-oaf average 八 scanf(=%dwdwd=cnumenu32cnu33=sumHnurrd+nu

4、m2+num3 八 averageHsunv3oPrinff(=su3f dbverageuf .ZArrysurrlbverage)八.3#include main()*/int hour,minute,second,total; /* 定义变量代表时、分、秒和总秒数 scanf(%d,&total);hour=total/3600; minute=total%3600/60;second=total%3600%60; printf(%dhours:%dminutes:%dsecondsn,hour,minute,second);第4章1.2.3.(1) 6 (2) 4 (3)

5、 1 (4) 1 (5)34.(1) b (2) b (3) b (4) b (5) b#include main( )int x,y;scanf(%d,&x);if (x-5 & x0 & x10) y=2*x+1;printf(x=%d,y=%dn,x,y); 5.#include main( ) int score,rank; /* score 表示成绩 ,rank 表示级别 */ printf(Please input score:);scanf(%d,&score); rank=score/10;switch(rank)case 9: printf( 成绩等级为：case 8: pr

6、intf( 成绩等级为：case 7: printf( 成绩等级为：case 6: printf( 成绩等级为： default:printf( 成绩等级为： An); break; Bn); break; Cn); break; Dn); break; En); break;6.#include void main()int n; printf(Please input the digit:); scanf(%d,&n);switch(n)case 1:printf(Jan n);break; case 2:printf(Feb n);break; case 3:printf(Mar n);

7、break; case 4:printf(Apr n);break; case 5:printf(May n);break; case 6:printf(Jun n);break; case 7:printf(Jul n);break; case 8:printf(Agu n);break; case 9:printf(Sep n);break; case 10:printf(Oct n);break; case 11:printf(Nov n);break; case 12:printf(Dec n);break;1.2.3.(1) b7,1y=-1m=610,14(2) a (3) b (

8、4) d (5) c第5章7.8.ABABCDCD9.x=8,y=2210.&n211.# include main ( )int i; long int sum=0;for (i=2;i=200;i+=2) sum+=i;printf(2+4+6+.+200=%ld,sum);.#include main()long int n;int sum = 0;printf(Please input the nber:); scanf(%ld,&n);while(n != 0)sum += n % 10; n /= 10;printf(%dn, sum);第6章(1) d (2) b

9、 (3) d (4) c56891134.5.12,66.i-7.char k; ij8.#include main( )float a10;int i;float sum=0,average;for (i=0;i10;i+)printf(a%d=?,i); scanf(%f,&ai);sum+=ai;average=sum/10;printf(average is %.2fn,average);9.#include #define N 10 main( )int aN,i,target,found;for (i=0;iN;i+)scanf(%d,&ai); printf(Please inp

10、ut a number:); scanf(%d,&target); i=0;while(iN & target != ai)i+; found = iN?i:-1; printf(%dn,found);#include #define N 80main( )..8.char strN;int len=0,i=0;printf(Please input a string:); gets(str);while (stri+ != 0) len+;printf(the length of string is %d.n,len); 2113616funcm+1,6,3,2

11、,32,5,1,2,3,-2#include int fun(int a,int b,int c); main( )int a,b,c,max; printf(Please input three numbers:); scanf(%d%d%d,&a,&b,&c); max=fun(a,b,c);printf(Max is %d.n,max);int fun(int a,int b,int c)int max;max= ab?(ac?a:c):(bc?b:c); return max;#include 第7章14.long int sum(int n); main( )int n;printf

12、(n=?); scanf(%d,&n); printf(Sum=%ld.n,sum(n);long int sum(int n)if (n = = 1 ) return 1; else return sum(n-1)+n;10.#include void fun(n);main( )int n;printf(n=?); scanf(%d,&n); fun(n);void fun(n)if (n = = 0) return; elsefun(n/2); printf(%-2d,n%2);第8章1.(1) b (2) d (3) b (4) c (5) c2.12345678945

13、6.7.*(br+i)8.bcdefgha9.p=sum10.#include #include main()char str80; char *p1, *p2; gets(str); p1=str;p2=str+strlen(str)-1; while (p1p2 & *p1+ = *p2- ) ;puts( p1p2 ? 不是回文 : 是回文 );.5.第9章a. #define F(x) (x)*(x)*(x)b. #define F(x) (x)%4c. #define F(x,y) (x)*(y)100?1:0a. 4b. 4c. #define DOUBLE(x) 2

14、*(x)-20N is undefinedy=6#include #define SWAP(a,b) int temp;temp=a;a=b;b=temp;.main()int x,y;printf(x=?);scanf(%d,&x);printf(y=?);scanf(%d,&y);SWAP(x,y)printf(x=%d,y=%d.n,x,y);1.第 10 章struct student int sno; char sname10; char sex;stu1,stu2; 4 3 9 88.合法的有 a,b,dc.改成 s.u.rectangle.len

15、gth=25;e.改成 s.u.circle.radius=5;f.改成 s.u.circle.radius=5;4.5.a,b,c,d (说明：变量 b 有确定的值之后， b+ 是合法的。 ) 改为typedef struct productchar name10; float price;PRODUCT;PRODUCT products10;6.struct employee printemp(emp)#include struct time_structint hour;int minute;int second;main( )struct time_struct time;printf

16、(Input time?n(Example 18:28:38)n);scanf(%d:%d:%d,&time.hour,&time.minute,&time.second);printf(Time is %d:%d:%dn,time.hour,time.minute,time.second); 9.#include struct time_structint hour;int minute;int second;time;void enter_time();void display_time();main( ) enter_time(); display_time();void enter_t

17、ime() printf(Enter the time(example 18:28:38)?); scanf(%d:%d:%d,&time.hour,&time.minute,&time.second);void display_time()printf(Time is %d:%d:%d.n,time.hour,time.minute,time.second);10.#include #define N 3 struct hotelchar name31; /* 旅馆名称 */ char address31;/* 旅馆地址 */ int grade; /* 旅馆级别 */ float aver

18、age_charge; /* 平均房价 */ int number; /* 房间数量 */hN=h1, 上海路 ,5,500.00,80,h2, 北京大街 ,5,480.00,70, h3, 南京大街 ,3,300.50,100 ;main( )int grade,i;printf( 请输入级别 (3-5)?); scanf(%d,&grade);for (i=0;iN;i+)if (hi.grade=grade)printf( 名称 :%sn 地址 :%sn 级别 :%dn 平均房价 %.2fn 房间数量 :%dn, ,hi.address,hi.grade,hi.averag

19、e_charge,hi.number);第 11 章1.(1) c(2) d(3) b (4) b (5) b2.Basican3.fgetc(fp)4.record.dat”,a ?w”5.#include #include #include typedef struct Employee int id;char name20; char gender20; int age;char address20; Employee;int main(void)FILE *fp;char another,choice; Employee emp;long int recsize;fp=fopen(em

20、ployee.dat,rb+);if(fp=NULL)fp=fopen( employee.dat,wb+);if(fp=NULL)printf(Cant Open File); exit(0); recsize=sizeof(emp);while(1)printf(1. 添加记录 2.显示男员工 3.退出 n);printf(Enter your choice(1-3):);fflush(stdin);scanf(%c,&choice); switch(choice)case1: fseek(fp,0,SEEK_END); another=Y;while(another=Y| another

21、=y)printf( 输入信息 (id 姓名 性别 年龄 住址 ):n);scanf(%d %s %s %d %s,&emp.id,&,&emp.gender,&emp.age,&emp.address);fwrite(&emp,recsize,1,fp);printf( 是否继续 (Y/N): );fflush(stdin);another=getchar();break;case 2:printf(”学号t姓名t性别t年龄t住址n);rewind(fp);while(fread(&emp,recsize,1,fp)=1)if (strcmp(emp.gender, 男)=0

22、)printf(%dt%st%st%dt%sn,emp.id,,emp.gender,emp.age,emp.address);break; case 3:fclose(fp);exit(0);6.#includestdio.h #includestdlib.h #define M 2 #define stu struct student stuint num; char name20; float s1; float s2; float s3; float avg;main()stu stM;FILE *fp;int i;printf(请输入5名同学生的成绩，按照学号,姓名咸绩1,成绩2,成绩3的顺序冲间 用空格隔开 :n);f