Question

用c语言编写函数求表达式1－1/2+1/3－1/4+1/5－1/6+1/7－…+1/n的值

详细些！

Answer 1

#include <stdio.h>
main()
{
int n,sign=1,i;
double sum=0.0;
printf("Enter n:");
scanf("%d",&n);
for(i=1;i<=n;i++)
{
sum+=sign*1.0/i;
sign=-sign;
}
printf("sum=%lf\n",sum);
}

Answer 2

#include <stdio.h>
void main()
{
int n,i;
float sum=0.0;
printf("Please enter n:");
scanf("%d",&n);
for(i=1;i<=n;i++)
{
if(i%2==1) sum+=1.0/i;
else sum-=1.0/i;
}
printf("sum=%lf\n",sum);
}