第五次作业

1编写程序，使用while语句求和sum1+2+3+5+…+21.

#include<stdio.h>

main()

{

        int i=1;int sum=0;

        while(i<=21)

        {

                 sum+=i;

                 i+=2;

        }

        printf("Sum=%d\n",sum);

}

编写程序，使用while语句求和sum=1+1/3+1/5+…+1/n。

#include<stdio.h>

main()

{

        int i=1;double sum=0;

        int n;

        scanf("%d",&n);

        while(i<=n)

        {

                 sum+=1.0/i;

                 i+=2;

       

        }

        printf("sum=%f\n",sum);

}

 

3编写程序，使用while语句求阶乘f=1x2x3x…xn

 

#include<stdio.h>

main()

{

 

        int i=1;long f=1;

        int n;

        scanf("%d",&n);

        while(i<=n)

        {

                 f*=i;

                 i++;

        }

        printf("f=%ld\n",f);

       

}

 

4打印出所有的“水仙花数”，

#include<stdio.h>

main()

{

        int a,b,c;

        int i=100;

        while(i<1000)

        {

                 a=i/100;

                 b=i%100/10;

                 c=i%10;

        if(i==a*a*a+b*b*b+c*c*c)

        printf("%4d",i);

            i++;

        }

}

 

 

5.输入两个数,输出他们中间的数

#include<stdio.h>

main()

{

 

        int a,b,i;

        printf("请输入两个数：\n");

        scanf("%d%d",&a,&b);

        i=a+1;

        while(i<=b-1)

        {

                 printf("%d\n",i);

                 i++;

                        

        }

}

6输出1-100既能被3又能被5整除的数的和

#include<stdio.h>

main()

{

 

        int a;

        a=1;

        while(a<=100)

        { 

                 if(a%3==0&&a%5==0)

                 printf("%d\n",a);

                 a++;

                        

        }

}