- #include
- using namespace std;
-
- int main()
- {
- //1.定义变量
- double e = 1.0f;
- double factorial = 1.0f;
- int n = 0;
- //2.输入数据
- cin >> n;
-
- for(int i = 1; i <= n; i++)
- {
- factorial = factorial * i;
- e += 1.0 / factorial;
- }
-
- printf("%.10lf",e);
- return 0;
- }