C语言程序设计 高等教育出版社第四章 课后答案

-练习4一3#include<stdio.h>#include<math.h>voidmain(){doubleeps,sjtemflag,denominator;s=0;item=1;flag=1;denominator=1;printf("Entereps:");scanf("%lf",&eps);while(fabs(item)>=eps){item=flag/denominator;s=s+item;flag=-flag;denominator=denominator+3;}printf("s=%lf\n",s);}练习4—4#include<stdio.h>voidmain(){intnum,n;floatscore,total=0;num=0;n=0;printf("Pleaseinputscore#1:");scanf("%f",&score);while(score>=0){if(score<60)num++;total=total+score;n++;printf("Pleaseinputscore#%d(0~100):",n+1);scanf("%f*',&score);}printf("Theaveragescoreis%.2f.\n",total/n);printf("Thenumbersbetween0and59is%d.\n",num);练习4-7#include<stdio.h>voidmain(){inti,j,n,num;printf("Entern:");scanf("%d",&n);fOr(i=1;i<=n;i++){printf("Pleaseinputaninteger:");scanf("%d",&num);fOr(j=2;j<=num-1;j++)if(i%j==0)break;if(j>num-1&&num!=1)printf("%disaprime.\n",num);elseprintf("%disnotaprimeW^num);}}练习4-8#include<stdio.h>voidmain(){intij，n;doublee,product;e=1;printf("Entern:");scanf("%d",&n);for(i=1;i<=n;i++){product=1;for(j=1;j<=i;j++)product=product*j;e=e+1/product;}printf("e=%.2lf\n",e);}练习4-11#include<stdio.h>voidmain(){inti,n,min,num;printf("Entern:");scanf("%d",&n);fOr(i=1;i<=n;i++){printf("Enteraninteger:");scanf("%d",&num);if(i==1)min=num;elseif(num<min)min=num;}printf("TheMinnumberis%d.\n",min);}练习4-12#include<stdio.h>voidmain(){intnum19num2=09flag=1;printf("Enteraninteger:");scanf("%d",&num1);if(num1<0){flag=-1;num1=-num1;}while(num1!=0){num2=num2*10+num1%10;num1=num1/10;}num2=flag*num2;printf("Thenewnumberis%d.\n'',num2);}练习4-13#include<stdio.h>voidmain()intij,count=0;for(i=100;i<=200;i++){for(j=2;j<=i-1;j++)if(i%j==0)break;if(j>i-1){count++;if(count%8==0)printf("%8d\n"ji);elseprintf("%8d",i);printf("\n");}练习4-14#include<stdio.h>voidmain(){int侦1=1f2=1,f;printf("%8d\n"f1);printf("%8d\n"f);/*输出前两项*/for(i=3;i<=20;i++){f=f2;f2=f1+f2;f1=f;printfC'%8d\n"f);printf("\n");}习题4-1#include<stdio.h>voidmain(){intnum=1,sum=0;while(num>0)printf("Enteraninteger:");scanf("%d",&num);if(num<=0)break;if(num%2==0)sum=sum+num;}printf("Thesumis%d.\n",sum);}习题4—2#include<stdio.h>#include<math.h>doublefact(intn);voidmain(){inti=1;doublex,item,s=0;printf("Enterx:");scanf("%lT,&x);item=x;while(fabs(item)>=0.00001){s=s+item;i++;item=pow(x,i)/fact(i);}printf("Thesumis%lf.\n",s);}doublefact(intn){inti;doubleproduct=1;for(i=1;i<=n;i++)product=product*i;returnproduct;}习题4—3#include<stdio.h>voidmain()intnum,sum=0,count=0;printf("Enteraninteger:")；scanf("%d",&num);if(num<0)num=-num;while(num>0){sum=sum+num%10;num=num/10;count++;}printf("Thesumis%d.\n",sum);printf("Thecountis%d.\n",count);}习题4—4#include<stdio.h>voidmain(){inti,n;doubleab,x,sum;a=2;b=1;sum=0;/*a为分子，b为分母*/printf("Enteraninteger:");/*输入项数*/scanf("%d",&n);for(i=1;i<=n;i++)/*求前n项之和*/{sum=sum+a/b;x=a+b;b=a;a=x;}printf("Thesumis%lf.\n",sum);/*输出和*/}习题4—5#include<stdio.h>voidmain()doubleitem,sum;/*item为项变量，sum为累加和变量*/sum=0;printf("Entertwointegersaandn:");scanf("%d%d",&a,&n);for(i=1;i<=n;i++)/*求前n项之和*/{item=0;fOr(j=1;j<=i;j++)/*求第i项*/item=item*10+a;sum=sum+item;}printf("Thesumis%lf.\n",sum);/*输出和*/}习题4-6#include<stdio.h>voidmain(){inti,j,k,count;/*count为换法种数，i为1分的硬币数，j为2分的硬币数，k为5分的硬币数*/count=0;for(i=1;i<=100;i++)for(j=1;j<=50;j++)for(k=1;k<=20;k++)if(i+2*j+5*k==100){printf("1分=%山2分=%山5分=%d\n",ij,k);count++;}printf("换法种数=%d\n",count);}习题4-7#include<stdio.h>voidmain(){inti9m9digit9sum;/*sum为各位数字的立方和变量*/for(i=1;i<=10000;i++)/*求整数i中各位数字的立方和*/m=i;sum=0;while(m!=0)digit=m%10;sum=sum+digit*digit*digit;m=m/10;}if(i==sum)printf(H%d\nH9i);/*输出满足条件的整数i*/}}习题4-8#include<stdio.h>intprime(intn);voidmain(){intm,i;for(m=6;m<=100;m=m+2)fOr(i=2;i<=m-1;i++)if(prime(i)&&prime(m-i)){printf("%d=%d+%d\n"9m9i9m-i);break;}}intprime(intn)/*判定n是否素数的函数，返回1表示素数，返回0表示非素数*/{intiflag;flag=1;/*初值为1*/fOr(i=2;i<=n-1;i++)if(n%i==0){flag=0;break;}/*置flag为0,表示非素数*/returnflag;}习题4-9#include<stdio.h>voidmain(){longintm,n,pow,digit;/*m为长整数变量，pow为m的幂*/printf("Enteralonginteger:");/*输入一个长整数m*/scanf("%ld",&m);/*求长整数m的幕，存放在pow变量中*/n=m;pow=1;while(n!=0){n=n/10;pow=pow*10;}pow=pow/10;/*从m的最高位开始，逐位输出各数位上的数字*/while(m!=0){digit=m/pow;/*求最高位数字*/m=m%pow;pow=pow/10;/*幂pow缩小10倍*/printf("%d"digit);}printf("\n");}习题4-10#include<stdio.h>voidmain(){inti,m,n;printf("Enteranintegerm:");/*输入一个正整数m*/scanf("%d",&m);n=m/2;printf("%d=1",m);for(i=2;i<=n;i++)while(m%i==0){printf("*%d",i);m=m/i;}printf("\n");习题4-11#include<stdio.h>voidmain(void){intm,n,j,k;/*j表示最小公倍数，k表示最大公约数*/printf("Inputtwointegermandn:");scanf("%d%d",&m,&n);j=m;while(j%n!=0)/*求最小公倍数，存放在j变量中*/j=j+m;k=(m*n)/j;/*求最大公约数，存放在k变量中*/printf("最小公倍数是％d\n最大公约数是％d\n",j,k);}习题4-12#include<stdio.h>voidmain(void){inti;doubleh,s;/*h为高度，s为总路程*/h=100;s=100;/*赋初值*/for(i=1;i<10;i++)/*循环9次，求出第10次落地的总路程*/{h=0.5*h;s=s+2*h;}h=0.5*h;/*第10次反弹的高度*/printf("第10次落地的总路程是％鸣第10次反弹的高度是％lf\n",s,h);}习题4-13#include<stdio.h>voidmain(void)intij;for(i=1;i<=7;i++)if(i<=4)/*输出图形的上4行*/{for(j=1;j<=20-2*i;j++)printf("");/*输出行前的空格*/for(j=1;j<=2*i-1;j++)printf(H*");/*输出一行中的**/}else/*输出图形的下3行*/{for(j=1j<=12+2*(i-