C程序设计(第3版)(谭浩强 著)部分课后习题答案(主要是第6,7,8章).docx

C程序设计（第三版）部分课后习题答案（谭浩强 著）6.4求n=120n!源代码如下：#includefloat factorial(int n)/定义阶乘函数int i;float product=1;for(i=1;i=n;i+)product=product*i;return product;int main(void)int j;float sum=0;for(j=1;j=3;j+)sum+=factorial(j);printf(%gn,sum);return 0;6.6 “水仙花数”源代码如下：#include#includeint fun(int num)int i=0;int array3;int sum=0;while(num)arrayi=num%10;i+;num=num/10;for(i=0;i3;i+)sum+=pow(arrayi,3);return sum;int main()int j;printf(输出所有的“水仙花数”：n);for(j=100;j=999;j+)if(j=fun(j)printf(%-7d,j);printf(n);return 0;6.7 完数源代码如下：#include#define M 20void main()int i,j;int sum;int arrayM;/用于存放“完数”的数组int k=0;/数组下标int n;/“完数”的个数for(i=1;i=1000;i+)sum=0;for(j=1;j=i/2;j+)if(i%j=0)sum=sum+j;if(sum=i)arrayk=i;k+;printf(输出“完数”及其因子：n);n=k;for(k=0;kn;k+)printf(%d its factors are ,arrayk);for(j=1;j=arrayk/2;j+)if(arrayk%j=0)printf(%d,j);printf(n);7.14 比较两个字符串源代码如下：#include#include#define M 20void main()char s1M,s2M;/定义两个字符串数组int len1,len2;int max_len;int i;int d;printf(Input the string one:n);gets(s1);printf(Input the string two:n);gets(s2);len1=strlen(s1);len2=strlen(s2);max_len=len1len2?len1:len2;/求二者中的较大值for(i=0;imax_len;i+)d=s1i-s2i;if(d!=0)break;printf(The result after comparing is %d.n,d);8.3 判断素数的算法 源代码如下：#include#includeint Prime(int number)int i;double k;k=sqrt(number);for(i=2;ik)return 1;elsereturn 0;int main()int num;int result;printf(Input a integral number:n);scanf(%d,&num);if(num=1)printf(%d既不是素数也不是合数。n,num);return 0;result=Prime(num);if(result)printf(%d is a prime number.n,num);elseprintf(%d is not a prime number.n,num);return 0;8.4 对33的矩阵实现转置源代码如下：#includevoid Transpose(int array_13)int i,j;int array_233;for(i=0;i3;i+)for(j=0;j3;j+)array_2ji=array_1ij;for(i=0;i3;i+)for(j=0;j3;j+)array_1ij=array_2ij;void main()int a33;int i,j;printf(输入一个33的矩阵：n);for(i=0;i3;i+)for(j=0;j3;j+)scanf(%d,&aij);Transpose(a);printf(转置矩阵为：n);for(i=0;i3;i+)for(j=0;j3;j+)printf(%-5d,aij);if(j=2)printf(n);8.5 对字符串进行反序处理源代码如下：#include#include#define N 20void Reverse(char* pointer,int len)int i;char temp;for(i=0;ilen/2;i+)temp=pointeri;pointeri=pointerlen-1-i;pointerlen-1-i=temp;void main()char strN;int length;/字符串长度printf(Input a string:n);gets(str);length=strlen(str);Reverse(str,length);printf(The new string:n);puts(str);8.6 对两个字符串进行连接处理源代码如下：#includevoid my_strcat(char*pointer1,char*pointer2)while(*pointer1)pointer1+;while(*pointer2)*pointer1=*pointer2;pointer1+;pointer2+;*pointer1=NULL;void main()char str130,str210;printf(Input string A:n);gets(str1);printf(Input string B:n);gets(str2);my_strcat(str1,str2);printf(The string A&B:n);puts(str1);8.8 将“1990”转换成“1 9 9 0”源代码如下：#includevoid fun(int num)int array14,array27;int i=0;while(num)array1i=num%10;num=num/10;i+;for(i=0;i4;i+)array1i=array1i+0;/将数字转化为相应的字符for(i=0;i4;i+)array22*i=array1i;for(i=0;i=0;i-)printf(%c,array2i);/以字符的形式输出void main()int number;printf(输入一个4位数字：n);scanf(%d,&number);printf(输出形式为：n);fun(number);printf(n);8.11 对字符数组进行排序源代码如下：#includevoid sort(char pointer)int i,j;char temp;for(j=0;j9;j+)for(i=0;ipointeri+1)temp=pointeri;pointeri=pointeri+1;pointeri+1=temp;void main()char array10=a,s,d,f,g,h,j,k,l,x;int i;printf(输入的10个字符为：n);for(i=0;i10;i+)printf(%-5c,arrayi);printf(n);sort(array);printf(The sorted numbers:n);for(i=0;i10;i+)printf(%-5c,arrayi);printf(n);8.13 递归算法求勒让德多项式的值源代码如下：#includefloat legendre_fun(int n, float x)/递归算法float value;if(n=0)value=1;if(n=1)value=x;if(n=2)value=(2*n-1)*x-legendre_fun(n-1,x)-(n-1)*legendre_fun(n-2,x)/n;return value;void main()int n;float x,value;printf(输入勒让德多项式的阶数与自变量的值：n);scanf(%d%f,&n,&x);value=legendre_fun(n,x);printf(勒让德多项式的值为：n);printf(%fn,value);6.1 求两个正整数的最大公约数和最小公倍数源代码如下：#includevoid main()int m,n;int r;int GCD;/最大公约数int LCM;/最小公倍数int product;/乘积int temp;printf(Input two positive integers:n);scanf(%d%d,&m,&n);product=m*n;if(mn)temp=m;m=n;n=temp;r=m%n;while(r)m=n;n=r;r=m%n;GCD=n;LCM=product/GCD;printf(The GCD is %d.n,GCD);printf(The LCM is %d.n,LCM);6.11 迭代法求非负数的算术平方跟源代码如下：#include#includefloat my_sqrt(float a)float x1,x2=a;while(fabs(x1-x2)=1e-5)x1=x2;x2=(x1+a/x1)/2;return x2;int main()float num;float result;printf(输入一个正实数：n);scanf(%f,&num);if(num0)printf(Math error!n);return 0;if(num=0)printf(算术平方根是0。n);return 0;elseresult=my_sqrt(num);printf(算术平方根是%f。n,result);return 0;7.9 折半法查找算法源代码如下：#includevoid main()int array15=15,14,13,12,11,10,9,8,7,6,5,4,3,2,1;int num;int i=0,j=14;int k;printf(输入一个整数：n);scanf(%d,&num);while(i=j)k=(i+j)/2;if(num=arrayk)printf(数组中的第%d个数。n,k+1);break;else if(numj)printf(无此数。n);7.11 打印 * 型平行四边形源代码如下：#include#include#define M 50int main(void)int n;char ch1=*;char ch2= ;int i,j;char arrayMM=0;printf(输入需打印的行数：n);scanf(%d,&n);for(i=0;in;i+)for(j=0;ji+n;j+)if(ji)arrayij=ch2;elsearrayij=ch1;printf(Output:n);for(i=0;in;i+)for(j=0;ji+n;j+)if(arrayij=ch2)printf(%-3c,arrayij);elseprintf(%-4c,arrayij);if(j