Question

编写函数，函数的功能是求是s=1-1/2+1/3-1/4+1/5-1/6+1/7-…+1/n, 把所求结果作为函数值返回。

Answer 1

main()
{
float qh(int);
int n;
float sum;
scanf("%d",&n);
sum=qh(n);
printf("%f",sum);
getch();
}
float qh(int n)
{
float sum=1;
int i;
for(i=2;i<=n;i++)
if(i%2==0) sum=sum-1.0/i;
else sum=sum+1.0/i;
return sum;
}

Answer 2

vb/vbscript/asp
function nadd(n)
nadd = 1
for i = 2 to n
if i mod 2 = 0 then
nadd = nadd - 1/i
else
nadd = nadd + 1/i
end if
next
end function

Answer 3

void main()
{
float sum=1.0,a=1.0;
for (i=2;i<=n;i++)
{
if (i%2==0) sum=sum-a/i;
else sum=sum+a/i;
}
printf("%f",sum)
}