c语言程序设计课后习题解答

1、第 3 章 习题解答第1章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)3.源程序：#includemain( ) printf( printf( printf( 4. 源程序： #include main( ) int a, b, c; /* scanf( “ %d” scanf( “ %d” c=a-b; /* printf( 5.Hello World!n”);n”);定义变量 */, &a); /*输入第一个整数, &b); /*输入第二个整数计算差 */%d-%d=%”d ,a,b,c); /*);*/*/输出结果 */(1) (2) x=1

2、0;(3) printf( “ s=%d n” ,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. =4,y=6b. x=4,y=3=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=%.2f n” ,x,y);4.#includemain()int

3、num1,num2,num3,sum;float average;scanf(%d%d%d,&num1,&num2,&num3);sum=num1+num2+num3;average=sum/;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=total%3600%60;printf(%dhours:%dmi

4、nutes:%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:);scanf(%d,&score); rank=s

5、core/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;Cn); break;Dn); break;En); break;case 7: printf(成绩等级为：case 6: printf(成绩等级为：default:printf(成绩等级为： 6.#includevoid main()int n;printf(Please input the digit:); scanf(%d,&n);switch(n)case 1:printf(Jan n);brea

6、k;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 12:printf(Dec n);brea

7、k;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 += n % 10;n /= 10;pri

8、ntf(%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 10main( )int aN,

9、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(the length

10、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?(ac?a:c

11、):(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); printf

12、(%-2d,n%2);第8章1.(1) b(2) d(3) b(4) c(5) c2. 83. 94. 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. #define F

13、(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 studentint s

14、no;char sname10;char sex;stu1,stu2;2. 123. 合法的有 a,b,dc. 改成e. 改成f. 改成b+是合法的。 )4. a,b,c,d ( 说明：变量 b 有确定的值之后，5. 改为typedef struct productchar name10;float price;PRODUCT;PRODUCT products10;6.(1) struct employee(2) printemp(emp)7. 2 4 3 9 88.#include struct time_struct int hour; int minute; int second; ma

15、in( )struct time_struct time;printf(Input time?n(Example 18:28:38)n); scanf(%d:%d:%d,&,&,&;printf(Time is %d:%d:%dn,;9.#include struct time_struct int hour;int minute;int second;time;void enter_time();void display_time(); main( )enter_time(); display_time();void enter_time()printf(Enter the time(exa

16、mple 18:28:38)?); scanf(%d:%d:%d,&,&,&;void display_time()printf(Time is %d:%d:%d.n,;10.#include #define N 3struct hotelchar name31; /* 旅馆名称 */char address31;/* 旅馆地址 */int grade; /* 旅馆级别 */float average_charge; /*平均房价 */int number; /* 房间数量 */hN=h1, 上海路 ,5,80,h2, 北京大街 ,5,70,h3, 南京大街 ,3,100;main( )int

17、 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.average_charge,hi.number);第 11 章1.(1) c(2) d(3) b(4) b(5) b2. Basican3. fgetc(fp)4. “”, “w”5.#include #include #include typedef struct E

18、mployeeint 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(,rb+);if(fp=NULL)fp=fopen( ,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); pri

19、ntf(Enter your choice(1-3):);fflush(stdin); scanf(%c,&choice);switch(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,&,&,&,&,&; fwrite(&emp,recsize,1,fp); printf( 是否继续 (Y/N): );fflush(stdin); another=getchar(); break;cas

20、e 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,男 )=0)printf(%dt%st%st%dt%sn,break;case 3: fclose(fp);exit(0);6.#include#include#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+)scanf(%d%s%f%f%f,&sti.num,s