计算1/1-1/2+1/3-1/4+1/5 …… + 1/99 - 1/100 的值

#include<stdio.h>
#include<stdlib.h>

int main() {
	int i = 1;
	double a = 1.0;
	double b = 2.0;
	while (b < 101) {
		i = -i;
		a = a + i * 1 / b;
		++b;
	}
	printf("%f\n", a);
	system("pause");
	return 0;
}