C程序第五章

5.1
#include<stdio.h>
int main()
{
int i=1,sum=0;
while(i<=100)
{
sum=sum+i;
i++;}
printf(“sum=%d\n”,sum);
return 0;
}

5.2
#include<stdio.h>
int main()
{
int i=1,sum=0;
do
{
sum=sum+i;
i++;
}
while(i<=100);
printf(“sum=%d\n”,sum);
return 0;
}

5.3
#include<stdio.h>
int main()
int i,sum=0;
printf(“please enter i,i=?”);
scanf("%d",&i);
while(i<=10)
{
sum=sum+i;
i++;
}
printf(“sum=%d\n”,sum);
return 0;
}

5.4
#include<stdio.h>
#define SUM 100000
int main()
{
float amount,aver,total;
int i;
for(i=1,total=0;i<=1000;i++)
{
printf(“please enter amount:”);
scanf("%f",&amount:);
total=total+amount;
if(total>=SUM)break;
}
aver=total/i;
printf(“num=%d\naver=%10.2f\n”,aver);
return 0;
}

5.5
#include<stdio.h>
int main()
{
int i;
for(n=100;n<=200,n++)
{
if(n%3==0)
continue;
printf("%d",n);
}
printf("\n");
return 0;
}

5.6
#include<stdio.h>
int main()
{
int i,j,n=0;
for(i=1,i<=4;i++)
for(j=1;j<=5;j++,n++)
{
if(n%50)printf("\n");
printf("%d\t",ij);
}
printf("\n");
return 0;
}

5.7
#include<stdio.h>
#include<math.h>
int main()
{
int sign=1;
double pi=0.0,n=1.0,term=1.0;
while(fabs(term)>=1e-6)
{
pi=pi+term;
n=n+2;
sign=-sign;
term=sign/n;
}
pi=pi4;
printf(“pi=%10.8f\n”,pi);
return 0;
}

5.8
#include<stdio.h>
int main()
{
int f1=1.f2=1,f3;
int i;
printf("%12d\n%12d\n",f1,f2);
for(i=1;i<=38;i++)
{
f3=f1+f2;
printf("%12d\n",f3);
f1=f2;
f2=f3;
}
return 0;
}

5.9
#include<stdio.h>
int main()
{
int n,i;
printf(“please enter a integer number,n=?”);
scanf("%d",&n);
for(i=2;i<=n-1;i++)
if(n%i0)break;
if(i<n)printf("%d is not a prime number.\n",n);
else printf("%d is a prime number.\n",n);
return 0;
}