计算1/1-1/2+1/3-1/4+1/5 …… + 1/99

#include <stdio.h>#pragma warning (disable:4996)#include <windows.h>int main(){double a = 1.0;  double sum = 1.0 / a;int i = 2;for ( i = 2; i <= 100; i++){if (i % 2 == 0){sum -= 1.0 / i;}else{sum += 1.0 / i;}}printf("%lf", sum);system("pause");return 0;}

程序运行结果：