c语言程序设计(科学出版社)课后习题解答

1、第 3 章 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( )精选范本printf(“ *n” );printf( printf( 4.源程序：);Hello Worlnd” ! );“ *#include main( )int a, b, c; /* 定义变量 */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

2、,c); /* 输出结果 */ 5.(1)(2)x=10;(3)printf( “ s=n%” d,s);第2章1.(1) c(2) a(3) b g(4) a d e(5) d2. a. 5 b. 295 c. 4 d. 29 e. 93. a.x=4,y=6b. x=4,y=3f.x=3,y=64. 165.#includemain()int a,b,c;scanf(%d%d,&a,&b);c=a*b;printf(%d*%d=%d,a,b,c);第3章1.(1) b(2) b(3) d(4) a(5) b2.(1)&a,&b(2)l,s3. printf(“ x=%.2f,y=%n ”.

3、2f,x,y);4.#includemain()int num1,num2,num3,sum;float average;scanf(%d%d%d,&num1,&num2,&num3);sum=num1+num2+num3;average=sum/3.0;printf(sum=%d,average=%.2fn,sum,average);5.#includemain()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=tota

4、l%3600%60;printf(%dhours:%dminutes:%dsecondsn,hour,minute,second);第4章1.(1) a(2) b(3) b(4) b(5) b2. 03.(1) 6(2) 4(3) 1(4) 14.#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:);

5、scanf(%d,&score);rank=score/10;switch(rank)case 10:case 9: printf(成绩等级为：An); break;case 8: printf(成绩等级为：Bn); break;case 7: printf(成绩等级为：Cn); break;case 6: printf(成绩等级为：Dn); break;default:printf( 成绩等级为：En); break; 6.#include void main()int n;printf(Please input the digit:);scanf(%d,&n);switch(n)case

6、1:printf(Jan n);break;case 2:printf(Feb n);break;case 3:printf(Mar n);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 1

7、2:printf(Dec n);break;第5章1.(1) b(2) a(3) b(4) d(5) d2. 7,13. y=-14. m=65. 10,146. 37. 58. ABABCDCD9.# include main ( )int i;long int sum=0;for (i=2;i=200;i+=2)sum+=i;printf(2+4+6+.+200=%ld,sum);10.#include main()long int n;int sum = 0;printf(Please input the nber:);scanf(%ld,&n);while(n != 0)sum +=

8、n % 10;n /= 10;printf(%dn, sum);第6章1.(1) d(2) b(3) d(4) c(5) a2. 113. 34. 56895. 12,66. (1) i- (2) n7. (1) char k; (2) 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

9、main( )int aN,i,target,found;for (i=0;iN;i+)scanf(%d,&ai);printf(Please input a number:);scanf(%d,&target);i=0;while(iN & target != ai)i+;found = iN?i:-1;printf(%dn,found);10.#include #define N 80main( )char strN;int len=0,i=0;printf(Please input a string:);gets(str);while (stri+ != 0) len+;printf(t

10、he length of string is %d.n,len);第7章1. 212. 1363. 164. (1) func (2) m+5. 96. 1,6,3,2,37. 2,5,1,2,3,-28.#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?

11、(ac?a:c):(bc?b:c);return max;9.#include long int sum(int n);main( )int n;printf(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);

12、printf(%-2d,n%2);第8章1.(1) b(2) d(3) b(4) c(5) c2. 83. 1234567894. 2 3 4 5 65. 3456. 1 2 3 4 5 67. bi8. 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 );第9章1.a. #define F(x) (x)*(x)*(x)b. #

13、define F(x) (x)%4c. #define F(x,y) (x)*(y)100?1:02.a. 4b. 4c. #define DOUBLE(x) 2*(x)3. d4. -205. N is undefined6. 7.57. y=68.#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);第 10章1.struct studentin

14、t sno;char sname10;char sex;stu1,stu2;2. 123. 合法的有 a,b,dc.改成 s.u.rectangle.length=25;e.改成 s.u.circle.radius=5;f. 改成 s.u.circle.radius=5;4. a,b,c,d (说明：变量b 有确定的值之后， b+ 是合法的。 )5. 改为typedef struct productchar name10;float price;PRODUCT;PRODUCT products10;6.(1) struct employee(2) printemp(emp)7. 2 4 3 9

15、 88.#include struct time_structint hour;int minute;int second;main( )struct time_struct time;printf(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 s

16、econd;time;void enter_time();void display_time();main( )enter_time();display_time();void enter_time()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 3s

17、truct hotelchar name31; /* 旅馆名称 */char address31;/俅馆地址 */int grade; /* 旅馆级别 */float average_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

18、:%sn 地址 :%sn 级别 :%dn 平均房价 %.2fn 房间数量 :%dn, ,hi.address,hi.grade,hi.average_charge,hi.number);第11章1.(1) c(2) d(3) b(4) b(5) b2. Basican3. fgetc(fp)4. “ record.dat ” ,“ w”5.#include #include #include typedef struct Employeeint id;char name20;char gender20;int age;char address20;Employee;int mai

19、n(void)FILE *fp;char another,choice;Employee emp;long int recsize;fp=fopen(employee.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);switc

20、h(choice)case1:fseek(fp,0,SEEK_END);another=Y;while(another=Y| another=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

21、 住址 n);rewind(fp);while(fread(&emp,recsize,1,fp)=1) if (strcmp(emp.gender,男)=0)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 studentstuint 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,成绩1,成绩2,成绩3 的顺序,中间用空格隔开 :n);for(i=0;iM;i+