计算1-1/2+……—1/100的值

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
int main()
{
	int i;
	double tmp = 1;
	double sum = 0;
	for (i = 1; i <= 100; i++)
	{
		tmp = 1.0 / i*(i % 2 == 0 ? -1 : 1);
		sum += tmp;
	}
	printf("%lf\n", sum);
	system("pause");
	return 0;
}