第五次作业

1.编写程序，使用while语句求和sum=1+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);

 

}

 

2.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do—while语句求阶乘

         #include<stdio.h>

main()

{

int i=1;long f=1;

         int n;scanf("%d",&n);

         do

         {

                  f*=i;

                  i++;

         }

         while(i<=n);

         printf("f=%ld\n",f);

}

 

4.编写程序，p61（4）.

#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);

         }

}

 

5．编写程序

#include<stdio.h>

main()

{

                  int a,b,i;

                  printf("请输入两个数:");

                  scanf("%d%d",&a,&b);

                  for(i=a+1;i<b;i++)

                  {

                          printf("%d",i);

                  }

}

 

6．编写程序

#include<stdio.h>

main()

{

         int i=1;int sum=0;

         while(i<=100)

         {

                  if(i%3==0&&i%5==0)

                  {

                  sum+=i;

                  }

                          i+=1;

                  }

         printf("它们的和为:%d\n",sum);

}