33: subtraction calculation value of the expression scores

33: subtraction calculation value of the expression scores

#include <stdio.h>
int main()
{
	double sum=0;int i,n;
	scanf("%d",&n);
	for(i=1;i<=n;i++)
	{
	    if(i&1)sum+=(1.0/i);
	    else sum-=(1.0/i);
	}
	printf("%.4lf\n",sum);
        return 0;
}