计算1-1/3+1/5-1/7.+1/101

Question

计算1-1/3+1/5-1/7等等+1/101

    int a;
    float sum=0.0;
    for(a=1;a<=101;a+=2)
    {
    sum=sum+1/a;
    a=-a;
}
printf("%f",sum);
return 0;

我这为什么运行没结果啊，没人告诉我我可能觉都睡不着了。

Answer 1

#include<stdio.h>
int main()
{
    int b=0;
    float a,sum=0;
    for (a = 1; a <= 101; a += 2)
    {
        if (b %2 == 0)
            sum += 1 / a;
        else
            sum += -1 / a;
        b++;    
    }
    printf("%f", sum);
    return 0;
}