C语言上机练习题及答案

1、1输入三个整数x,y,z,把这三个数由小到大输出。# include<stdio.h>voidmain()intx,y,z,a;scanf("%d,%d,%d",&x,&y,&z);if(x>y)a=x;x=y;y=a;if(x>z)a=x;x=z;z=a;if(y>z)a=y;y=z;z=a;printf("%d,%d,%dn",x,y,z);田2输入圆的半径，输出圆的周长和面积。# include<stdio.h># definePI3.1415926# defineS=PI*r*r#

2、 defineV(4.0/3)*PI*r*r*rvoidmain()doubler;printf("pleaseinputr:");scanf("%lf",&r);printf("areais%.4lfn",S);printf("volumeis%.4lfn",V);输入正方形的边长，输出正方形的周长和面积。# include<stdio.h>voidmain()floatc,zc,mj;printf("输入你的正方形");scanf("%fn",&

3、;c);zc=4*c;mj=c*c;printf("周长f,面积f,边长f",zc,mj,c);3用格式输入函数输入3个字符，并用输出函数反向输出3个字符和他们的ASCII码。# include<stdio.h>intmain()char-ch1,ch2,ch3;printf("pleaseinputthreecharacters:n");scanf("%C%C%c",&ch1,&ch2,&ch3);printf("%cn%dn",ch3,ch3);printf("%c

4、n%dn",ch2,ch2);printf("%cn%dn",ch1,ch1);f=9/5*c+32。输入一个摄氏温度，要求输出华氏温度。公式为# include<stdio.h>voidmain()floatC,F;scanf("%f",&F);C=5.0/9*(F-32);printf("%8.2f",C);4。比较两个数大小的题#include<stdio.h>voidmain()inta,b;scanf("%d,%d",&a,&b);if(a>

5、b)printf("%dn",a);elseprintf("%dn",b);第二题：此题作废(千万不要用)#include<stdio.h>voidmain()chara,b,c;scanf("%c,%c,%c",&a,&b,&c);while(a<97|a>122)|(b<97|b>122)|(c<97|c>122)；printf("您输入非三个小写字母，请重新输入：n");scanf("%c,%c,%c",&a,

6、&b,&c);printf("%c,%c,%cn",a-32,b-32,c-32);5输入任意10个数，求他们的平均值。#include<stdio.h>voidmain()Printf("请输入10个整数：");inta10,k=0,sum=0;for(inti=0;i<10;+i);i>ai;if10>=ai>0+k;sum=sum+ai;floatave=sum/10.0printf("平均值为：%fn",ave);6 实现从键盘输入两个整数，按从小到大次序输出这两个数。#in

7、clude<stdio.h>voidmain()inta,b,tem;printf("inputtwonumbers:n");scanf("%d,%d",&a,&b);if(a>b)tem=a;a=b;b=tem;printf("%d,%d",a,b);7 从键盘输入三个整数，输出最大的那个数。#include<stdio.h>voidmain()inta,b,c,max;printf("请输入三个整数：n");scanf("%d%d%d",&

8、;a,&b,&c);max=a>b?a:b;max=max>c?max:c;printf(“max=%dn”,max);8 输入任意一个三位数，将其各位数字反序输出(例如输入123，输出321)。#include<stdio.h>voidmain()intx,y,z,n;printf("pleaseinputanintegerlessthan1000n");scanf("%d",&n);x=n/100;n=n-100*x;y=n/10;z=n-10*y;if(x>0)printf("%d%d

9、%dn",z,y,x);elseif(y>0)printf("%d%dn",z,y);elseprintf("%dn",z);9 输入三角形的边长，求三角形面积。(面积=sqrt(s(s-a)(s-b)(s-c),s=(a+b+c)/2)。#include<stdio.h>voidmain()floata,b,c,s,area;intok=0;printf("inputa,b,c:");scanf("%f,%f,%f",&a,&b,&c);a+b>c?ok+

10、:0;a+c>b?ok+:0;b+c>a?ok+:0;ok=3(s=1/2*(a+c+b);area=sqrt(s*(s-a)*(s-b)*(s-c);printf("s=%fn,area=%fn",s,area);10输入2个数，比较其大小，将较大的数输出。#include<stdio.h>voidmain()inta,b,c,max,min;printf(“Inputa=”);scanf(“%d”,&a);printf(“Inputb=”);scanf(“%d”,&b);If(a>b)printf(“较大的数是%dn”,a)

11、;elseprintf(“较大的数是%dn”,b);11输入任意三个整数，求它们的和及平均值。#include“stdio.h"voidmain()inta,b,c,sum;floatave;scanf("%d%d%d",&a,&b,&c);sum=a+b+c;ave=(a+b+c)/3.0;printf("三个数的和为：%dn",sum);printf("三个数的平均值为：%fn",ave);12求解方程ax2+bx+c=0的实数根。a,b,c由键盘输入，aw0且b2-4ac>0。#inclu

12、de<stdio.h>#include<math.h>voidmain()floata,b,c,x1,x2;printf("请输入a,b,c的值：");scanf("%f%f%f",&a,&b,&c);if(b*b-4*a*c<=0)printf("输入的系数不对，b2-4ac不大于0！程序退出！n");elsex1=(-b+sqrt(b*b-4*a*c)/2*a;x2=(-b-sqrt(b*b-4*a*c)/2*a;printf("x1=%.2fn",x1);

13、printf("x2=%.2fn",x2);13 写一个程序，输入一个班学生的成绩，求全班的平均成绩。#include<iostream>usingnamespacestd;voidfailnum(intscore,intnum)intn=0;for(inti=0;i<num;i+)if(scorei<60)n+;cout<<"不及格人数："<<n<<endl;voidaverage_num(intscore,intnum)intsum=0,number=0;floatn=0;for(inti=

14、0;i<num;i+)sum=sum+scorei;n=(sum*1.0)/num;for(i=0;i<num;i+)if(scorei>=n)number+;cout<<"平均分为："<<n<<endl;cout<<"成绩在全班平均分及平均分之上的学生人数:"<<number<<endl;voidstastics(intscore,intnum)intn1=0,n2=0,n3=0,n4=0,n5=0;for(inti=0;i<num;i+)if(scorei

15、<60)n1+;elseif(scorei<=69)n2+;elseif(scorei<=79)n3+;elseif(scorei<=89)n4+;if(scorei>=90)n5+;cout<<"分数在60以下占："<<(n1*1.0)/num)*100<<"%"<<endl;cout<<"分数在60-69占："<<(n2*1.0)/num)*100<<"%"<<endl;cout<

16、<"分数在70-79占："<<(n3*1.0)/num)*100<<"%"<<endl;cout<<"分数在80-89占："<<(n4*1.0)/num)*100<<"%"<<endl;cout<<"分数在90以上占："<<(n5*1.0)/num)*100<<"%"<<endl;intmain()intscore35,num;cout&l

17、t;<"输入全班总人数："cin>>num;cout<<"输入内容(每个数不超出0-100)，用空格分开："<<endl;for(inti=0;i<num;i+)cin>>scorei;failnum(score,num);average_num(score,num);stastics(score,num);return0;14 编写程序输出如下图形：(没有的！)* * *从键盘输入一个整数判断是否为素数。#include"stdio.h"voidmain()inti,n;p

18、rintf("pleaseinputapositivenumber:");scanf("%d",&n);for(i=2;i<=n-1;i+)if(n%i=0)break;if(i<=n-1)printf("%d不是素数n",n);elseprintf("%d不是素数n",n);15输入一个三位数，判断是否是一个“水仙花数”，水仙花数是指3位数的各位数字的立方和等于这个三位数本身。例如153=1*1*1+5*5*5+3*3*3。#include<stdio.h>voidmain()in

19、tx,a,b,c;scanf("%d",x);a=x/100;b=(x/10)%10;c=x%10;if(x=a*a*a+b*b*b+c*c*c)printf("YES");elseprintf("NOT");16输入年号，判断它是否为闰年。#include<stdio.h>voidmain()inty;scanf("%d",&y);if(y%400=0|y%4=0&&y%100!=0)printf("Yes.n");elseprintf("No.n

20、");17用for循环语句求n!用递归法求n!#include<stido.h>intfac(intn);voidmain()(intn;printf("pleaseinputn(n>=0):");scanf("%d",&n);printf("%d!=%dn",n,fac(n);)intfac(intn)intt;if(n=0|n=1)t=1；elset=n*fac(n-1);elsereturn(t);18用函数实现求最大公约数的程序#include<stdio.h>intgcd(in

21、ta,intb);voidmain()inta,b,m;printf("pleaseinputa,b:");scanf("%d,%d",&a,&b);m=gcd(a,b);printf("gcd(%d,%d尸dn",a,b,m);intgcd(inta,intb)inttdot=a%d;a=b;b=t;while(b!=0);return(a);19用函数实现求最小公倍数的程序#include<stdio.h>intgcd(inta,intb);intlcm(inta,intb);voidmain()int

22、a,b,m,n;printf("pleaseinputa,b:");scanf("%d,%d",&a,&b);m=gcd(a,b);n=lcm(a,b);printf("gcd(%d,%d)=%dn",a,b,m);printf("lcm(%d,%d)=%dn",a,b,n);intgcd(inta,intb)inttdot=a%d;a=b;b=t;while(b!=0);return(a);intlcm(inta,intb)intt;t=a*b/gcd(a,b);return(t);20编写判断水仙花的函数，从主函数输入一个三位正整数N，在主函数中调用判断水仙花数的函数，求出三位数中所有的水仙花数。水仙花数是指3位数的各位数字的立方和等于这个三位数本身。例如153=1*1*1+5*5*5+3*3*3。#include<stdio.h>voidf(m)intx,y,z;x=m/100;y=m/10%10;z=m%10;if(m=x*x*x+y*y*y+z*z*z)printf("%d是水仙花数n",m);elseprintf("%d不是水仙花数n",m);voidmain()intn;scanf("%