C语言程序设计教程课后习题答案.doc

第1章1-3 CAB4 .c .obj .exe5 /* */6 ;7 算法8 中级语言：C语言具有高级语言的先进思想又能直接对存储器进行操作，能进行位运算，能实现汇编语言的大部分功能，生成目标代码质量高，程序执行效率高。结构化语言：C语言用函数作为程序模块,以实现程序的模块化，语言简洁、紧凑，具有结构化的特点。可移植性好：C语言不包含依赖硬件的输入输出机制，使C语言本身不依赖于硬件系统，可移植性好。9 #includemain( ) ; 10 #include “stdio.h” main()printf(“This is my first C Program!”);第2章1 yes2 -33 2,14 1)a!=b|a=4|x20&x30|x-1006 #include main()int x;printf(“please input an integar:”);scanf(%d,&x);if(x%5=0&x%7=0) printf(yesn);else printf(non);7.#include main()int year,month;printf(please input the year and month:);scanf(%d%d,&year,&month);switch(month)case 1:case 3:case 5:case 7:case 8:case 10:case 12:printf(this month have 31 days.); break;case 4:case 6:case 9:case 11:printf(this month have 30 days.); break;case 2:if(year%4=0&year%100!=0|year%400=0) printf(this month have 29 days.);break; else printf(this month have 28 days.);break; 8. #include main()float money;int year;printf(nplease input the money and the year:);scanf(%f%d,&money,&year);if(year=1) money+=money*0.00315*12*year; if(year=2) money+=money*0.00330*12*year; if(year=3|year=4) money+=money*0.00345*12*year; if(year=5&year=8) money+=money*0.00420*12*year;printf(the money is:%f,money);第3章1 #include stdio.hmain() float x10,sum=0; int i=0; printf(please input 10 numbers(-10e6x10e6)n); while(i10) scanf(%f,&xi); sum=sum+1/xi; i=i+1; printf(the sum of 10 numbers is %.2fn,sum);2#include stdio.hmain() int x100,sum=0,aver,i=0; printf(please input numbers until 0n); scanf(%d,&xi); while(xi!=0) sum=sum+xi; i=i+1; scanf(%d,&xi); printf(the sum is %dn,sum); printf(the average is %.2fn,float(sum)/i);3#include stdio.h#include math.hmain() int i=1,j,f; long int s=0; while(i=10) for(f=1,j=1;j=i;j+) f=f*j; s=s+pow(-1,i-1)*f; i=i+1; printf(s= %ldn,s);4#include stdio.h#include math.hmain() int i=0; float s=0.0; while(2*i+1=101) s=s+pow(-1,i)/float(2*i+1); i=i+1; printf(s= %fn,s);5#include stdio.h#includemath.hmain() int i,j,k,n=0; for(i=1;i=9;i+) for(j=0;j=9;j+) for(k=0;k=9;k+) if(i*100+j*10+k=i*i*i+j*j*j+k*k*k) printf(the %d:%dn,+n,i*100+j*10+k); printf(the all is %d.n,n-);6#include stdio.hmain() int n,i,j; printf(please input n:); scanf(%d,&n); for(i=0;in;i+) for(j=0;jn;j+) printf(*); printf(n); 7#include stdio.hmain() char a81; int i,j=0,k=0,m=0; printf(please input a $(length=65&ai=90) j+; else if(ai=32) k+; else m+; printf(the upper letter is %dn,j); printf(the blank is %dn,k); printf(the other is %dn,m);8#include stdio.hmain() int i,j,k,m=0; for(i=0;i=20;i+) for(j=0;j=50;j+) for(k=0;k=100;k+) if(i*5+j*2+k=100) printf(the %d wag is 1:%d,2:%d,5:%dn,+m,k,j,i); printf(the wags is %dn,m-); 9#include stdio.hmain() int i,j,k,m=0; for(i=0;i=3;i+) for(j=0;j=3;j+) for(k=0;k=6;k+) if(i+j+k=8) printf(the %d wag is white:%d,red:%d,black:%dn,+m,i,j,k); printf(the wags is %dn,m-); 10#include stdio.hmain() long int n; int i,j,k; printf(please inpur n:); scanf(%ld,&n); if(n%2=1|n=1) printf(the input is error.n); return(1); for(i=2;i=n/2;i+) for(j=2;ji;j+) if(i/j*j=i) break; if(j=i) for(k=2;kn-i;k+) if(n-i)/k*k=(n-i) break; if(k=n-i) printf(%ld=%d+%dn,n,i,n-i); 11#include stdio.hmain()int i,j,k,m; for(i=1;i=9;i+) for(j=0;j=9;j+) for(k=0;k=9;k+) for(m=0;m=A&stri=a&stri=0&stri=9) num2+; i+; printf(num1=%d,num2=%d,num1,num2);9笔者在程序中直接给数组元素赋了值，读者可以修改为用scanf函数读入数值；另外，还可以用第7章宏定义的方法设定数组的长度，从而实现对元素个数不同的数组进行排序。#include stdio.hmain() int a5=2,4,1,3,0,i,j,temp; for(i=0;i=4;i+) printf(%d,ai); printf(n); for(j=1;j=4;j+) for(i=j;i=4;i+) if(aiaj-1) temp=aj-1; aj-1=ai; ai=temp; for(i=0;i=4;i+) printf(%d,ai);第6章1-5 AADBA 6 C7 0 2 4 6 8 10 12 14 16 180 2 4 6 8 10 12 14 16 188 a+b=99 5+4+1=10 10+4+2=16 20+4+3=2710加密：#include stdio.hmain() char string100,i=0,number=0; scanf(%s,string); while(stringi+!=0) number+; fun1(string,number); printf(%s,string);fun1(char str,int num) int i; for(i=0;i=A&stri=a&stri=0&striV&striv&stri5&stri=9) stri-=6;解密#include stdio.hmain() char string100,i=0,number=0; scanf(%s,string); while(stringi+!=0) number+; fun2(string,number); printf(%s,string);fun2(char str,int num) int i; for(i=0;i=E&stri=e&stri=4&stri=A&stri=a&stri=0&stri4) stri+=6;第8章一、下列语句是否合法语句：int *p = &x, x = 13;点评：不合法，因为x变量没有定义。在执行int *p = &x 时，x变量的定义在后面。参考：int x = 13, *p = &x;语句：int *p = &x = 13;点评：不合法，因为x变量没有定义。在执行int *p = &x = 13 时，x变量没有定义。参考：int x = 13, *p; p = &x;语句：int x = 13,*p = x;点评：不合法，不能把x变量的值赋給指针p。应该把变量x的地址值赋給指针p。参考：int x = 13, *p; p = &x;语句：int y5 = 1,2,3,4,5,*p = y3;点评：不合法，不能把数组元素y3的值赋給指针p，应该把数组元素y3的地址值赋給指针p。参考：int y5 = 1,2,3,4,5,*p ; p = &y3;语句：int *p = y,y5 = 1,2,3,4,5;点评：不合法，因为数组y没有定义。参考：int y5 = 1,2,3,4,5,*p; p = y;语句：int y5 = 1,2,3,4,5,*p = &y;点评：不合法，不能把数组y的地址值赋給指针p。数组名y本身是数组y的地址常量值。参考：int y5 = 1,2,3,4,5,*p; p = y;或 int y5 = 1,2,3,4,5,*p; p = &y0;语句：int *c = &ch,ch = Hello World;点评：不合法，ch变量没有定义，字符串Hello World不能赋給变量ch。参考：char *ch = Hello World!;或char *ch;ch = Hello World;语句：char ch12 = Hello World,*c = ch;点评：合法。思考：char ch12 = Hello World！,*c = ch;该语句错误，字符个数超出数组ch定义的宽度。语句：char *c = ch12 = Hello World点评：不合法，数组ch没有定义。数组ch没有第12个元素。参考：char *c,ch12 = Hello World;c = ch;语句：char *c,c = X,c = &c;点评：不合法，不能把常量X的值赋給指针，不能把指针c的地址值赋給指针c自己。参考：char *c,ch; ch = X,c = &ch;二、综合练习题参考答案1将一字符串复制到另一字符串中。#includevoid main()char str1128,str2128 = Welcome to C Language;char *cp1,*cp2;cp1 = str1;cp2 = str2;while(*cp1+ = *cp2+);puts(str1);2将一字符串与另一字符串相连接。#includevoid main()char str1128 = Welcome ,str2128 = to C Language;char *cp1,*cp2;int i = 0,n = 0;while(n+,str1+i != 0);cp1 = str1+n;cp2 = str2;while(*cp1+ = *cp2+);puts(str1);3将字符数组中大写字符改为小写字符，将小写字符改为大写字符。#includevoid main()char str1128 = Welcome to C Language;char *cp1 = str1;while(*cp1)if(*cp1 = A & *cp1 = a & *cp1 = z) *cp1 = *cp1-32;else*cp1 = *cp1;cp1+;puts(str1);4从一字符串中取出部分字符串复制到另一字符串中。#includevoid main()char ch128,*cp,str128,*sp;int b,n,l=0,i;cp=ch;sp=str;gets(cp);scanf(%d%d,&b,&n);while(l+,*(ch+l)!=0);if(nl)for(i=0;in;i+)*(sp+i)=*(cp+b+i);*(sp+i)=0;puts(str);elseprintf(无数据可以复制);5完成一整型数组的排序。#include#includevoid main()int x10,i,j,*p,t;p = x;for(i = 0;i10;i+)xi = rand();for(i = 0;i9;i+)for(j = 0;j*(p+j+1)t = *(p+j);*(p+j) = *(p+j+1);*(p+j+1) = t;for(i = 0;i10;i+)printf(%dt,*p+);6将一个字符串中的字符反序排列。#includevoid main()char ch128,c,*cp1,*cp2;int i,n = 0;gets(ch);cp1 = ch;cp2 = ch;while(*cp2!= 0)n+;cp2+;cp2-;n = n/2;for(i = 0;in;i+)c = *cp1;*cp1 = *cp2;*cp2 = c;cp1+;cp2-;puts(ch);7编函数完成将一字符串中的字符全部改为大写。#includevoid cove(char *cp)while(*cp!= 0)if(*cp= a & *cp= z)*cp = *cp-32;cp+;void main()char ch128,*cp;cp = ch;gets(cp);cove(cp);puts(ch);8编函数完成从一字符串左边取若干字符复制到另一字符串中。#includevoid lm(char *lcp,char *bcp,int n)int i;for(i = 0;in;i+)*(bcp+i) = *(lcp+i);*(bcp+i) = 0;void main()char ch128,*cp,str128;int n,l =0;gets(ch);scanf(%d,&n);while(l+,*(ch+l)!= 0);if(nl)cp = ch;lm(cp,str,n);puts(str);elseprintf(无数据可以复制);第9章1#include stdio.hstruct date int year; int month; int day;main() struct date re; int day212=31,29,31,30,31,30,31,31,30,31,30,31,31,28,31,30,31,30,31,31,30,31,30,31; int i,days=0; printf(input the day(year:month:day):n); scanf(%d:%d:%d,&re.year,&re.month,&re.day); if(re.year%4=0&re.year%100!=0)|re.year%400=0) for(i=1;ire.month;i+) days+=day1i-1; else for(i=1;ire.month;i+) days+=day0i-1; days+=re.day; printf(the days is %dn,days);2#include stdio.hmain()enum weekdaySun,Mon,Tue,Wed,Thu,Fri,Sat day; int data; printf(input the data:); scanf(%d,&data); data+=2; day=(enum weekday)(data%7); switch(day) case Mon:printf(It is Monday.n);break; case Tue:printf(It is Tuesday.n);break; case Wed:printf(It is Wednesday.n);break; case Thu:printf(It is Thursday.n);break; case Fri:printf(It is Friday.n);break; case Sat:printf(It is Saturday.n);break; case Sun:printf(It is Sunday.n);break; default:printf(errorn); 3#include stdio.hstruct result int notpass; int pass; int good;main() struct result re, *p=&re; int i,temp; void output(struct result *); re.notpass=0; re.pass=0; re.good=0; printf(input 12 integers;n); for(i=0;i12;i+) scanf(%d,&temp); if(temp100) printf(error!n); return(0); else if(temp=80) re.good+; else re.pass+; output(p); return(1);void output(struct result *p) printf(the result:n); printf( mark: 0-59 60-79 80-100n); printf(number: %d %d %dn,p-notpass,p-pass,p-good);4#include stdio.hstruct stat int length; int blank; int letter; int number;main() struct stat re2; char temp; int k; void output(struct stat *); for(k=0;k2;k+) rek.length=0; rek.blank=0; rek.letter=0; rek.number=0; for(k=0;k=65&temp=97&temp=48&templength=(p+1)-length) printf(the length of 2 strings is equal.n); else printf(the length of 2 strings is different.n); if(p-blank=(p+1)-blank) printf(the amounts of blanks in 2 strings is equal.n); else printf(the amounts of blanks in 2 strings is different.n); if(p-letter=(p+1)-letter) printf(the amounts of letters in 2 strings is equal.n); else printf(the amounts of letters in 2 strings is different.n); if(*p).number=(p+1)-number) printf(the amounts of numbers in 2 strings is equal.n); else printf(the amounts of numbers in 2 strings is different.n);第10章 1、C文件的特点是：C系统在处理文件时，并不区分类型，都看成是字符流，按字节进行处理。 输入输出字符流的开始和结束只由程序控制而不受物理符号(如回车符)的控制。因此C语言文件也叫流式文件。流式文件准许对一个字符进行存取, 这增加了数据处理的灵活性。缓冲文件系统：缓冲文件系统自动在内存区开辟一个确定大小的缓冲区，使数据输入输出都先通过缓冲区。非缓冲文件系统：非缓冲文件系统不自动开辟确定大小的缓冲区，而是由程序员为每个文件设定一个缓冲区。2、文件类型指针是缓冲文件系统的一个重要概念。文件类型指针是指向描述文件信息结构体的结构体变量，用于文件操作。在C语言中，对普通数据文件的所有操作都必须依靠文件类型指针来完成。要想对文件进行操作，首先必须将想要操作的数据文件与文件指针建立联系，然后通过这些文件指针来操作相应的文件。3、打开文件，是建立文件的各种有关信息，并使文件指针指向该文件，以便进行其它操作。关闭文件则断开指针与文件之间的联系，也就禁止再对该文件进行操作。4、C语言程序中，文件操作顺序为：打开读/写关闭。5、#include #define NULL 0main()FILE *fp;char ch;int linenum,chnum,i=0,l=0;fp=fopen(FILE.C,r);if(fp=NULL) printf(File cant be opened.n); exit(1); ch=fgetc(fp);linenum=0;chnum=0;while(ch!=EOF)while(ch!=n)chnum+;ch=fgetc(fp);linenum+;if (ichnum)i=chnum;l=linenum;chnum=0;ch=fgetc(fp);printf(nthe longest line is the %d line,and there are %d characters.,l,i);fclose(fp);第11章1、#include #include #define NULL 0typedef int ElemType;typedef struct LNode ElemType data; struct LNode *next; LNode,*LinkList;LNode* create_LinkList(int n)/*创建链表*/LNode *s,*head,*L;ElemType x;int k=0;L=(LNode *)malloc(sizeof(LNode);if(L=0)printf(error!);exit(1);elseL-next=NULL;head=L;while(kdata=x;s-next=NULL;L-next=s;L=s;k+;return (head);void print_LinkList(LinkList L)/*输出链表*/LNode *h;h=L;while(h-next!=NULL)printf( %d ,h-next-data);h=h-next;int num_LinkList(LinkList L)int i=0;while(L-next!=0)i+;L=L-next;return i;LNode* Insert(LinkList L,ElemType x)int k,i;LNode *s,*z,*l;s=L-next;k=num_LinkList(L);for(i=0;idatanext;else break;z=(LNode *)malloc(sizeof(LNode);if(z=0)printf(error!);exit(1);z-data=x;if(s=NULL) l-next=z;z-next=NULL;elseif(i=0)L-next=z;z-next=s;elsel-next=z;z-next=s;return L;main()LNode *la;ElemType x;int num;clrscr();printf(please input the elements of la,small to big:n);la=create_LinkList(10);printf(nthe elements of the la are:);print_LinkList(la);printf(nplease input the inserted element x:);scanf(%d,&x);la=Insert(la,x);print_LinkList