计算1/1-1/2+1/3-1/4+1/5......+1/99-1/100 (c语言)

注意因为定义的是doublde 类型，所以要用1.0而不是1
sum用来求正项
ret用来求负项
w来求总和

//计算1/1-1/2+1/3-1/4+1/5.....+1/99-1/100的值
#include 
#include 
int main(){
 int n;
 double w, sum = 0.0, result = 0.0;
 for (n = 1; n <= 100; n += 2)
  sum = sum + 1.0 / n;         //因为是小数，所以也要用小数除，要用1.0，用1的话运行结果是错的
 for (n = -2; n >= -100; n -= 2)
  result = result + 1.0 / n;
 w = result + sum;
 printf("%f", w);
 system("pause");
 return 0;
}