20131003国庆作业第五章例5-1,5-3.5-4

5-1

#include<stdio.h>
int main(void)
{
    double height,radius,volume;
    double cylinder(double r,double h);

    printf("Enter radius and height:");
    scanf("%lf%lf",&radius,&height);
    volume=cylinder(radius,height);
    printf("Volume=%.3f
",volume);

    return 0;
}
double cylinder(double r,double h)
{
    double result;

    result=3.1415926*r*r*h;

    return result;
}

5-3

#include<stdio.h>
#include<math.h>
int main(void)
{
    double e,pi;
    double funpi(double e);
    printf("Enter e:");
    scanf("%lf",&e);
    pi=funpi(e);
    printf("pi=%f
",pi);

    return 0;
}
double funpi(double e)
{
    int denominator,flag;
    double item,sum;

    flag=1;
    denominator=1;
    item=1.0;
    sum=0;
   
    while(fabs(item)>=e){
        item=flag*1.0/denominator;
        sum=sum+item;
        flag=-flag;
        denominator=denominator+2;
    }

    return sum*4;
}

5-4

#include<stdio.h>
#include<math.h>
int main(void)
{
    int count,m;
    int prime(int m);

    count=0;
    for(m=2;m<=100;m++){
        if(prime(m)!=0){
            printf("%6d",m);
            count++;
            if(count%10==0) printf("
");
        }
    }
    printf("
");
}