break;
}
}
2.12
#include <stdio.h>
main()
{
int a,k=0;
printf("please input data:");
scanf("%d",&a);
while(a%2==0)
{
a=a/2;
k++;
}
printf("\nthe number of factor(2) is %d",k);
}
2.13
main()
{
long i,t=1;
long sum=0;
for(i=1;i<=10;i++)
{
t*=i;
sum+=t;
printf("%ld!=%ld\n",i,t);
}
printf("sum:%ld\n",sum);
}
2.14
#include <stdio.h>
void main()
{
int i,x=0;
for(i=9;i>=1;i--)
{
x=2*(x+1);
}
printf("The first day:%d",x);
}
2.15
#include <stdio.h>
#define PI 3.141593
main()
{
float r,h;
float v;
printf("please input r,h:");
scanf("%f%f",&r,&h);
v=1.0/3*PI*r*r*h;
printf("V=%.2f",v);
}
2.16
#include<stdio.h>
#include<math.h>
main()
{
long int sn=0;
long int m=0,t=0;
int a,n,i;
printf("please input a n:");
scanf("%d%d",&a,&n);
for(i=0;i<n;i++)
{
m=m*10+a;
sn+=m;
}
printf("a+aa+aaa+...+aa...a=%ld\n\n",sn);
}
2.17
#include <stdio.h>
main()
{
int k;
printf("please input k:");
do
{
scanf("%d",&k);
if(k>=0&&k<=6)
break;
}while(1);
switch(k)
{
case 0:printf("Sunday.\n");break;
case 1:printf("Monday.\n");break;
case 2:printf("Tuesday.\n");break;
case 3:printf("Wednesday.\n");break;
case 4:printf("Thursday.\n");break;
case 5:printf("Friday.\n");break;
case 6:printf("Saturday.\n");break;
}
}
2.18
#include <stdio.h>
main()
{
int i;
double x,a,b=1,sum=1;
printf("please input x:");
scanf("%lf",&x);
a=x;
for(i=1;a/b>=1e-6;i++)
{
sum=sum+a/b;
a=a*x;
b=(i+1)*b;
}
printf("\nsum=%lf",sum);
}
2.19
#include <stdio.h>
#include <math.h>
main()
{
float a,x1,x2;
printf("input a:");
scanf("%f",&a);
x1=1.0;
while(1)
{
x2=1.0/2*(x1+a/x1);
if(fabs(x2-x1)<1e-5)
break;
x1=x2;
}
printf("sqrt(a)=%f",x2);
}
第四章
写出下列程序输出结果
1.no 1 a=1no 1 a=0no 1 a=1no 1 a=0
2.
a=0 b=0 c=0
a=1 b=0 c=0
a=2 b=0 c=0
3.
main:x=5,y=1,n=1
func:x=6,y=21,n=11
main:x=5,y=1,n=11
func:x=8,y=31,n=21
1.D
2.D
3.C
4.6
5.CDABC
6.(1)j+=2
(2)a[i]<a[j]
7.(1)s[i++]!='\0'
(2)s[i-1]
8.D
9.B
10.6(同题4)
11.s[i]>='0'&&s[i]<='9'
12. (1)'\0' (2)str1[i]-str2[i]
5.1
#include<stdio.h>
int fun();
int fun()
{
int a[3][3],sum; 第五章
int i,j;
sum=0;/*error*/
for(i=0;i<3;i++)
{
for(j=0;j<3;j++)
scanf("%d",&a[i][j]);/*error*/
}
for(i=0;i<3;i++)
sum=sum+a[i][i];
printf("sum=%d\n",sum);
}
void main()
{
fun();
}
5.2
#include <stdio.h>
void main( void )
{
float Num[10];
float Input,GetNum[11];
int i,j;
float a=6;
for(i=0; i<10; i++)
{
Num[i]=a;
a=a+7.5;
}
Loop1: printf("Please input a Number(0-80) Input=");
scanf("%f",&Input);
if((Input<0)||(Input>70)==1)
goto Loop1;
for(i=0; i<10; i++ )
{
if(Input<Num[i])
goto Loop2;
}
Loop2: for(j=0; j<i; j++ )
GetNum[j]=Num[j];
GetNum[j]=Input;
for(j=i; j<=10; j++,i++)
GetNum[j+1]=Num[i];
for(j=0; j<11; j++ )
printf("%3.3f ",GetNum[j]);
}
5.3
#include "stdio.h"
#include "stdlib.h"
main()
{
int a1,a2,a3,a4,a5,a6,a7,a8,a9;
int a[3];
int i;
for(;;)
{
for (i=0;i<3;i++)
{
a[i]=rand()%3;
}
while((a[0]!=a[1]) && (a[0]!=a[2]) && (a[1]!=a[2]))/*get three different numbers 0,1,2*/
{
a1=a[0]+1;/*divide 1~9 into three groups,a1~a3,a4~a6,a7~a9*/
a2=a[1]+1;
a3=a[2]+1;
a4=a1+3;
a5=a2+3;
a6=a3+3;