C程序设计课后习题答案(第8章).doc

（1）#includevoid main()int hcf(int,int);/*zui da gong yue shu*/int lcd(int,int,int);/*zui xiao gong bei shu*/int u,v,h,l;scanf(%d,%d,&u,&v);h=hcf(u,v);printf(H.C.F=%dn,h);l=lcd(u,v,h);printf(L.C.D=%dn,l);int hcf(int u,int v)int t,r;if(uv)t=u;u=v;v=t;while(r=u%v)!=0)u=v;v=r;return v;int lcd(int u,int v,int h)return(u*v/h);（2）#include#includefloat x1,x2,disc,p,q;void main()void greater_than_zero(float,float);void equal_to_zero(float,float);void smaller_than_zero(float,float);float a,b,c;printf(ninput a,b,c:);scanf(%f,%f,%f,&a,&b,&c);printf(equation:%5.2f*x*x+%5.2f*x+%5.2f=0n,a,b,c);disc=b*b-4*a*c;printf(root:n);if(disc0)greater_than_zero(a,b);printf(x1=%fnx2=%fn,x1,x2);else if(disc=0)equal_to_zero(a,b);printf(x1=x2=%fn,x1);elsesmaller_than_zero(a,b);printf(x1=%f+%finx2=%f-%fin,p,q,p,q);void greater_than_zero(float a,float b)x1=(-b+sqrt(disc)/(2*a); x2=(-b-sqrt(disc)/(2*a);void equal_to_zero(float a,float b)x1=x2=(-b)/(2*a);void smaller_than_zero(float a,float b)p=(-b)/(2*a); q=sqrt(-disc)/(2*a);（3）#includevoid main()int prime(int);int n;printf(ninput an integer:);scanf(%d,&n);if(prime(n) printf(n %d is a prime.n,n);else printf(n %d is not a prime.n,n);int prime(int n)int flag=1,i;for(i=2;in-1;i+)if(n%i=0)flag=0;break;return flag;（4）#include#define N 3int arrayNN;void main()void convert(int array3);int i,j;printf(input array:n);for(i=0;iN;i+) for(j=0;jN;j+) scanf(%d,&arrayij); printf(noriginal array:n);for(i=0;iN;i+) for(j=0;jN;j+) printf(%5d,arrayij); printf(n);convert(array);printf(convert array:n);for(i=0;iN;i+) for(j=0;jN;j+) printf(%5d,arrayij); printf(n);void convert(int array3)int i,j,t;for(i=0;iN;i+) for(j=i+1;jN;j+) t=arrayij; arrayij=arrayji; arrayji=t; （5）#include#includevoid main()void inverse(char str);char str100;printf(input string:);scanf(%s,str);inverse(str);printf(inverse string:%sn,str);void inverse(char str)char t;int i,j;for(i=0,j=strlen(str);i(strlen(str)/2;i+,j-)t=stri;stri=strj-1;strj-1=t;（6）#includevoid main()void concatenate(char string1,char string2,char string);char s1100,s2100,s100;printf(ninput string1:);scanf(%s,s1);printf(input string2:);scanf(%s,s2);concatenate(s1,s2,s);printf(The new string is %sn,s);void concatenate(char string1,char string2,char string)int i,j;for(i=0;string1i!=0;i+) stringi=string1i;for(j=0;string2j!=0;j+) stringi+j=string2j; stringi+j=0;（7）#includevoid main()void cpy(char s,char c);char sty80,c80;printf(ninput string:);gets(sty);cpy(sty,c);printf(nThe vowel letters are:%sn,c);void cpy(char s,char c)int i,j;for(i=0,j=0;si!=0;i+)if(si=a|si=A|si=e|si=E|si=i|si=I|si=o|si=O|si=u|si=U)cj=si;j+;cj=0;（8）#include#includevoid main()char str80;void insert(char str);printf(input four digits:);scanf(%s,str);insert(str);void insert(char str)int i;for(i=strlen(str);i0;i-)str2*i=stri; str2*i-1= ; printf(output:n%sn,str);（9）#includeint letter,digit,space,others;void main()void count(char str);char text80;printf(nplease input string:n);gets(text);printf(string:);puts(text);letter=0;digit=0;space=0;others=0;count(text);printf(letter:%d,digit:%d,space:%d,others:%dn,letter,digit,space,others);void count(char str)int i;for(i=0;stri!=0;i+) if(stri=A&stri=a&stri=0&stri=9) digit+; else if(stri= ) space+; else others+;（10）#include#includevoid main()int alphabetic(char c);int longest(char string);int i;char line100;printf(input one line:n);gets(line);printf(The longest word is:);for(i=longest(line);alphabetic(linei);i+)printf(%c,linei);printf(n);int alphabetic(char c)if(c=a&c=A&c=Z)return 1;else return 0;int longest(char string)int len=0,i,length=0,flag=1,place=0,point;for(i=0;i=length) length=len; place=point; len=0; return place;（11）#include#include#define N 10char strN;void main()void sort(char str);int i,flag;for(flag=1;flag=1;)printf(input string:n);scanf(%s,&str);if(strlen(str)N) printf(string too long,input again!);else flag=0;sort(str);printf(string sorted:n);for(i=0;iN;i+) printf(%c,stri); printf(n);void sort(char str)int i,j;char t;for(j=1;jN;j+) for(i=0;(istri+1) t=stri; stri=stri+1; stri+1=t; （12）#include#includevoid main()float solut(float a,float b,float c,float d);float a,b,c,d;printf(input a,b,c,d:);scanf(%f,%f,%f,%f,&a,&b,&c,&d);printf(x=%fn,solut(a,b,c,d);float solut(float a,float b,float c,float d)float x=1,x0,f,f1;dox0=x;f=(a*x0+b)*x0+c)*x0+d;f1=(3*a*x0+2*b)*x0+c;x=x0-f/f1;while(fabs(x-x0)=1e-3);return x;（13）#includevoid main(