水题 - 1517 u Calculate e

 1 #include <iostream> 
 2 using namespace std;  
 3 
 4 // 5  120 
 5 // 6  720
 6 // 7  5040
 7 // 8  40320
 8 // 9  362880
 9 
10 int main(){
11     cout<<"n e"<<endl;
12     cout<<"- -----------"<<endl;
13     double ans[10] = {1,2,2.5,6,24,120,720,5040,40320,362880};
14     for(int i=0;i<3;++i){
15         cout<<i<<" "<<ans[i]<<endl;
16     }
17     cout.precision(10);
18     for(int i=3;i<10;++i){
19         ans[i] = ans[i-1] + (double)1.0/ans[i];
20         cout<<i<<" "<<ans[i]<<endl;
21     }
22 
23     return 0;  
24 }