计算1/1-1/2+1/3-1/4+1/5 …… + 1/99

计算方法以循环为主，需要注意的是精度问题。

#include<stdio.h>#include<stdlib.h>int main(){    int i = 0;    double sum = 0.0;    for(i = 1; i<=100; i++)    {        if(i%2==0)        {            sum = sum - (double)1/i;         }        else        {            sum = sum + (double)1/i;        }    }    printf("1/1+1/2+1/3+......+1/100结果为%f",sum);    system("pause");    return 0;}