c语言课后答案.doc

1、C语言习题答案第1章1选择题(1) C (2) B (3) D2填空题(1)main (2) main (3) 有穷性、确定性、有零个或多个输入、有一个或多个输出、有效性(4) 顺序、分支和循环(5) 自顶向下，逐步细化、模块化设计、结构化编码第2章1选择题BBCDA DDBBA BBDCB2、填空题 (1) 数字、字母、下划线 (2)0 (3) 4、8 (4) (a+b)*c/(a-b) (5) 60 （6）16（7）3 （8）6、4、2 （9）0 （10）10、6 （11）5.500000 （12） 12、4（13）double （14） 0 （15）16 （16）6.63、编程题（1）m

2、ain() printf(int:%5dn float:%5dn char:%5dn double:%5dn long:%5dn, sizeof(int), sizeof(float), sizeof(char), sizeof(double), sizeof(long);（2）#define RAT 1.60934main() float k=0.0; printf(input the km:); scanf(%f,&k); printf(nmile:%f,k*RAT);第3章1选择题(1) (10)：DDCDCDCDBC2解析题(1) x=170,x=170,x=252, x=170 x=

3、170,x=170,x=170,x=%6d a=513.789185,a=513.79,a=513.78918457,a=513.78918457(2) a=3b=7x=8.5y=71.82c1=Ac2=a3编程题(1)main() int x,y; scanf(%d%d,&x,&y); printf(商数=%d,余数=%d,x/y,x%y); system(pause);(2)main() double x,y,z,avg; scanf(%lf%lf%lf,&x,&y,&z); avg=(x+y+z)/3; printf(%.1lf,avg,avg); system(pause);第4章1选

4、择题(1)(10) CCAADCCABD2填空题(1) ch=A & ch=Z ch=ch-32(2) x2 x-1 y=-1(3) a+bc & a+cb & b+ca a=b&a=c a=b | a=c | b=c(4) mark/10 k=1 case 9(5) x0 c=x/10 y!=-23编程题(1)#include main() int x; printf(please input a number:); scanf(%d,&x); if(x%2=0) printf(x is a even number); else printf(x is a odd number);(2)#i

5、nclude main() int x,y; printf(please input a number); scanf(%d,&x); if(x=-5) printf(the number is error); else if(x0) y=x; printf(%d,y); else if(x=0) y=x-1;printf(%d,y); else if(x10) y=x+1;printf(%d,y); else printf(the number is error);(3)#include main() int a,m; printf(please input a number:); scan

6、f(%d,&a); switch(a/10) case 0: case 1: case 2:m=1;break; case 3:m=2;break; case 4:m=3;break; case 5:m=4;break; default:m=5;break; printf(%d,m);(4)#include main() float price,tax; printf(please input the price of product:); scanf(%f,&price); if(price10000) tax=price*0.05; else if(price5000) tax=price

7、*0.03; else if(price1000) tax=price*0.02; else tax=0; printf(%f,tax);(5)#include main() float score; printf(please input the score of student:); scanf(%f,&score); if(score=85) printf(VERY GOOD); else if(score=60) printf(GOOD); else printf(BAD);第5章1选择题(1)d (2) c (3)a (4)d (5)a (6)d (7)d (8)b (9)d (10

8、)b(11)c (12)b (13)d (14)a (15)c2填空题(1) =0 m=m/k k+ (2) 5 4 6 (3) 3*i-2(4) -= *= (5) 8 5 2 (6) j+ i%j=0 j=i (7)sumk sum=k j-2 (8) s=0 p=1 j=i 3改错题 (1) 第一处改正： For改为for 第二处改正： ave=sum/4改为ave=sum/4.0 (2) 第一处改正： j=9 第二处改正： m=100*i+10*j+k3编程题(1) #include main()int s;float n,t,sum;t=1; sum=0; n=1; s=1.0;wh

9、ile(n=100) sum=sum+t; n=n+1; s=-s; t=s/n;printf(sum=%10.6fn,sum);(2) 利用辗除法，直到b为0为止main() int p,r,n,m,temp; printf(input two integer n,m:); scanf(%d,%d,&n,&m); if(n0) x1=(x2+1)*2; /*第一天的桃子数是第2天桃子数加1后的2倍*/ x2=x1; day-; printf(thetotalis%dn,x1); (4)#include main() int i; long int n=1; for(i=1;i=10;i+)

10、n=n*i; printf(i%5=0?%2d!=%-10ldn:%2d!=%-10ld,i,n); (5)main() int m,s,i; for(m=2;m1000;m+) s=0; for(i=1;im;i+) if(m%i)=0) s=s+i; if(s=m) printf(%d its factors are ,m); for(i=1;im;i+) if(m%i=0) printf(%d,i); printf(n); (6)#include main() int n,i,j; scanf(%d,&n); for(i=1;i=n;i+) for(j=1;j=n+i-1;j+) if(

11、j=n-i) printf( ); else printf(*); printf(n); (7)#includemain() float x0,x1,x2,fx0,fx1,fx2; do printf(Enter x1 & x2:); scanf(%f,%f,&x1,&x2); fx1=x1*(2*x1-4)*x1+3)-6; fx2=x2*(2*x2-4)*x2+3)-6; while(fx1*fx20); do x0=(x1+x2)/2; fx0=x0*(2*x0-4)*x0+3)-6; if(fx0*fx1)=1e-5); printf(x=%6.2fn,x0);第6章1选择题CCDCC

12、 AADBD2. 写出程序的运行结果(1) sum=6 (2) Max=9,row=1,col=0 (3) 01 02 1 03 2 1 0(4) -53、填空（1）i=j=k=0 、 i4 、j5、（2） si 、 s0,s1 、str,s1、s2,str4、编程题（1）#include main() int a12,count=0,i; randomize();for (i=0;i12;i+) ai=5+random(11); for(i=0;i12;i+) printf(%5d,ai); count+; if(count%4=0)printf(n) ; getch();（2）main()

13、 int a5=2,23,43,77,33; int max,min,i; long sum=0L; int count=0; float av; max=min=a0; for(i=0;imax)max=ai; if(aimin)min=ai; av=(float)sum/5; for(i=0;iav)count+; printf(max:%dnmin:%dnav:%fncount:%d,max,min,av,count); getch();（3）main() int score30=61,62,63,64,65,66,67,68,69,70, 71,72,73,74,75,76,77,78

14、,79,80, 81,85,89,90,33,44,55,91,92,93; int i,count90=0,count80=0,count70=0,count60=0; for(i=0;i30;i+) printf(intput NO. %d students score:,i+1); scanf(%d,score+i); for(i=0;i=90) count90+; count80+; count70+; count60+; else if(scorei=80) count80+; count70+; count60+; else if(scorei=70) count70+; coun

15、t60+; else if(scorei=60) count60+; printf(060:%dn6070:%dn7080:%dn8090:%dn90100:%d,30-count60,count60-count70,count70-count80,count80-count90,count90); printf(n60 or higher:%dn70 or higher:%dn80 or higher:%dn90 or higher:%dn,count60,count70,count80,count90); getch();（4）1、main() char a45; int i,j,k; f

16、or(i=0;i45;i+)ai= ; for(i=0;i5;i+) for(j=0;ji;j+) a9*i+j= ; for(k=0;k5;k+) a9*i+j+k=*; j=0; for(i=0;i45;i+) printf(%c,ai); j+; if(j%9=0)printf(n); getch();2、main() char a59; int i,j,k; for(i=0;i5;i+) for(j=0;j9;j+) aij= ; for(i=0;i5;i+) for(j=0;ji;j+) aij= ; for(k=0;k5;k+) aij+k=*; for(i=0;i5;i+) fo

17、r(j=0;jy?x:y) （9） str =abdef (10) 8,17 (11)a=5a*a=25a*a*a=512(12)*#*#*#*3 、编程题(1) long act(long n) if (n=1|n=0) return 1L; else return n*act(n-1); main() int n=3; printf(n!=%ld,act(n); getch();（2）void mmax(float a,int n);main()float a6;int i;for(i=1;i=5;i+)scanf(%f,&ai);a0=1;mmax(a,5);printf(%f %fn,

18、aa0,a0);void mmax(float a,int n)if(naa0)a0=n;mmax(a,n-1);（3）#include main() char a40;int i=0;for(;i=40;i+)scanf(“%c”,&ai); int count=0,i=0,len,flag=0; len=strlen(a); while(!flag&ilen) if(ai=A)flag=1; i+; while(flag&i=A&(a)=a&(a)=z)main() char c; scanf(%c,&c); printf(%dn,ISALPHA(c); (2)/*习题8-2-2 */#d

19、efine SWAP(t,x,y) t w; w=x; x=y; y=w; main() double a=99.99,b=11.11; SWAP(double,a,b); printf(%f,%fn,a,b);(3)/*习题8-2-3 */#include stdio.h#define MAX 80#define CHANGE 1main() char strMAX; int i; printf(Input text:n); gets(str); #if(CHANGE) for (i=0;i=a&stri=A&striZ) stri+=1; else if(stri=z|stri=Z) st

20、ri-=25; #endif printf(output:n%s,str);(4)/*习题8-2-4 */#define LEAP_YEAR(y) (y%4=0)&(y%100!=0)|(y%400=0)main() int year; printf(Input year:); scanf(%d,&year); if(LEAP_YEAR(year) printf(%d is a leap year.n,year); else printf(%d is not a leap year.n,year);(5)/*习题8-2-5.h */#ifndef _X8_2_5_H#define _X8_2_

21、5_H#define AVER(a,b,c) (a+b+c)/3.0#endif/*习题8-2-5 */#include X8_2_5.hmain() int a,b,c; printf(Input three integers a,b,c:); scanf(%d,%d,%d,&a,&b,&c); printf(Average is %f.n,AVER(a,b,c);第9章4编程题(1)/*习题9-4-1 */#include #include main() char *str120,*str220,*str320; char swap(); printf(Input three line:n

22、); gets(str1); gets(str2); gets(str3); if(strcmp(str1,str2)0) swap(str1,str2); if(strcmp(str1,str3)0) swap(str1,str3); if(strcmp(str2,str3)0) swap(str2,str3); printf(Now, the order is:n); printf(%sn%sn%sn,str1,str2,str3);char swap (char *p1,char*p2) /*交换两个字符串*/ char *p20; strcpy(p,p1); strcpy(p1,p2)

23、; strcpy(p2,p);(2)/*习题9-4-2 */main() int number20,n,m,i; printf(How many numbers?); /*共有多少个数*/ scanf(%d,&n); printf(Input %d numbers:n,n); /*输入n个数*/ for(i=0;in;i+) scanf(%d,&numberi); printf(How many place you want to move?); /*后移多少个位置*/ scanf(%d,&m); move(number,n,m); /*调用move函数*/ printf(Now,they a

24、re:n); for(i=0;iarray;p-) *p=*(p-1); *array=array_end; m-; if(m0) move(array,n,m); /*递归调用，当循环次数m减至0时，停止调用*/(3)/*习题9-4-3 */#include #include#define TOTAL 7int mseek(char*str,char xstr,int n) int i; for(i=0; in; i+) if(strcmp(stri,xstr)=0) return 1; return 0; main() char*nameTOTAL=Lining,Linshan,Tiany

25、uan,Zhangqiang,Haipo,Fangbing; char xname20; printf(enter a name:); gets(xname); if(mseek(name,xname,TOTAL) printf(Found!n); else printf(Not found!n);(4)/*习题9-4-4 */#include #include int fun(char *str,int num4) int i; for(i=0; i=a & *str=A & *str=0 & *str=9) num2+; else num3+; str+; #define N 80main

26、() int stringN,n4,i; gets(string); fun(string,n); for(i=0; i4; i+) printf(%dt,ni);(5)/*习题9-4-5 */#include main() int a55,*p,i,j; void change(int *p); printf(Input matrix:n); for(i=0;i5;i+) /*输入矩阵*/ for(j=0;j5;j+) scanf(%d,&aij); p=&a00; /*使p指向0行0列元素*/ change(p); /*调用函数, 实现交换*/ printf(Now, matrix: n)

27、; for(i=0;i5;i+) /*输出已交换的矩阵*/ for(j=0;j5;j+) printf(%4d,aij); printf(n); void change(int *p) /*交换函数*/ int i,j,temp; int *pmax,*pmin; pmax=p; pmin=p; for(i=0;i5;i+) /*找最大值和最小值的地址,并赋给pmax,pmin*/ for(j=0;j5;j+) if(*pmax*(p+5*i+j) pmin=p+5*i+j; temp=*(p+12); /*将最大值换给中心元素*/ *(p+12)=*pmax; *pmax=temp; tem

28、p=*p; /*将最小值换给左上角元素*/ *p=*pmin; *pmin=temp; pmin=p+1; for(i=0;i5;i+) /*找第二最小值的地址赋给pmin*/ for(j=0;j*(p+5*i+j) pmin=p+5*i+j; temp=*pmin; /*将第二最小值换给右上角元素*/ *pmin=*(p+4); *(p+4)=temp; pmin=p+1; for(i=0;i5;i+) /*找第三最小值的地址赋给pmin*/ for(j=0;j*(p+5*i+j) pmin=p+5*i+j; /*将第三最小值换给左下角元素*/ temp=*pmin; *pmin=*(p+2

29、0); *(p+20)=temp; pmin=p+1; for(i=0;i5;i+) /*找第四最小值的地址赋给pmin*/ for(j=0;j*(p+5*i+j) pmin=p+5*i+j; temp=*pmin; /*将第四最小值换给右下角元素*/ *pmin=*(p+24); *(p+24)=temp;(6)/*习题9-4-6 */#include main() void avsco(float *psco,float *pave); void avcour1(char *pcou,float *psco); void fali2(char course510,int num4,floa

30、t score45,float aver4); void good(char course510,int num4,float score45,float aver4); int i,j,*pnum,num4; float score45,aver4,*psco,*pave; char course510,*pcou; printf(Input course: n); pcou=course0; for(i=0;i5;i+) scanf(%s,coursei); printf(Input NO. and scoures: n); printf(NO.); for(i=0;i5;i+) prin

31、tf(,%s,coursei); printf(n); psco=&score00; pnum=&num0; for(i=0;i4;i+) scanf(%d,pnum+i); for(j=0;j5;j+) scanf(,%f,psco+5*i+j); pave=&aver0; printf(nn); avsco(psco,pave); /*求出每个学生的平均成绩*/ avcour1(pcou,psco); /*求出第一门课的平均成绩*/ printf(nn); fali2(pcou,pnum,psco,pave); /*找出2门课不及格的学生*/ printf(nn); good(pcou,p

32、num,psco,pave); /*找出成绩好的学生*/void avsco(float *psco,float *pave) /*求每个学生的干均成绩的函数*/ int i,j; float sum,average; for(i=0;i4;i+) sum=0.0; for(j=0;j5;j+) sum=sum+(*(psco+5*i+j); /*累计每个学生的各科成绩*/ average=sum/5; /* 计算平均成绩*/ *(pave+i)=average; void avcour1(char *pcou,float *psco) /*第一门课的平均成绩的函数*/ int i; floa

33、t sum,average1; sum=0.0; for(i=0;i4;i+) sum=sum+(*(psco+5*i); /*累计每个学生的得分*/ average1=sum/4; /*计算平均成绩*/ printf(course 1: %s ,average score: %6.2f. n, pcou,average1);void fali2(char course510,int num4,float score45,float aver4) /*找两门以上课程不及格的学生的函数*/ int i,j,k,label; printf(= = = = = = = =Student who is

34、 fail = = = = = = = = = = = =n); printf( NO.); for(i=0;i5;i+) printf(%10s,coursei); printf( averagen); for(i=0;i4;i+) label=0; for(j=0;j5;j+) if(scoreij)=2) printf(%5d,numi); for(k=0;k5;k+) printf(%10.2f,scoreik); printf(%10.2fn,averi); void good(char course510,int num4,float score45,float aver4) /*

35、找成绩优秀的学生(各门85分以上或平均90分以上)的函数*/ int i,j,k,n; printf(= = = = = = = =Student whose score is good= = = = = = = =n); printf( NO.); for(i=0;i5;i+) printf(%10s,coursei); printf( averagen); for(i=0;i4;i+) n=0; for(j=0;j85.0) n+; if(n=5)|(averi=90) printf(%5d,numi); for(k=0;k5;k+) printf(%10.2f,scoreik); pri

36、ntf(%10.2fn,averi); (7)/*习题9-4-7*/#include double sigma(double (*fn)(double),double l,double u) double sum=0,d;for(d=l; du; d+=0.1) sum+=fn(d); return sum;void main() double sum; sum=sigma(sin,0.1,1.0);printf(sum of sin from 0.1 to 1.0 is: %fn,sum); sum=sigma(cos,0.5,3.0);printf(sum of cos from 0.5 to 3.0 is: %fn,sum);(8)/*习题9-4-8 */main() int i; char *month_name(int n); printf(input Month No.:n); scanf(