HDOJ - 1012 - u Calculate e（数学、水题）

方法：水题，注意阶乘递归的写法，输出问题。输出3以下的和3以上的分开。

AC代码：

#include <iostream>    #include <iomanip>    #include <string>    #include <cstring>    #include <cstdio>    #include <queue>    #include <stack>    #include <algorithm>    #include <cmath>    #include <ctime>using namespace std;  int fac(int n){if (1 == n || 0 == n)return 1;elsereturn n * fac(n-1);}void Calcu(int i){int j = 0;double sum = 0;for (j = 0; j <= i; j++)sum += 1.0/fac(j);if (i < 3)cout << i << " " << sum << endl;elsecout << i << " " << fixed << setprecision(9) << sum << endl;}int main(){#ifdef Local      freopen("a.in", "r", stdin);  #endifcout << "n e" << endl<< "- -----------" << endl;int i = 0;for (i = 0; i <= 9; i++)Calcu(i);return 0;}