Title links: http://wikioi.cn/problem/210799

 
# include 
# include 
using namespace std; 
Int main () 
{
Unsigned long long n; 
Double k=0.0; 
Cin> n; 
For (unsigned long long I=1; i<=n; I++) {
Unsigned long long v=1; 
For (unsigned long long j=1; j<=I; J++) {
V *=j; 
} 
K +=1.0/v; 
} 
Printf (" %. 10 f \ n ", k); 
return 0; 
} 

The problem is where I do wrong?
O give directions!
I write on their own compiler 10, are the result of 2.7182787698, 15, 2.7182818288, 2, 1.5000000000, yes
Why didn't to this problem is a test point?

CodePudding user response:

Have you set your initial value of k is 1.0

CodePudding user response:

In addition, unsigned long long not necessary, and to all the int, although does not affect the result, but this didn't asked for such a large integer types, are you afraid of v integer value is not big enough, it will be v type into a double line,

Specific you can look at the code

 # include 
# include 
using namespace std; 
Int main () 
{
int n; 
Double k=1.0; 
Cin & gt;> n; 
For (int I=1; i <=n; I++) {
A double v=1.0; 
For (int j=1; J & lt;=I; J++) {
V *=j; 
} 
K +=1.0/v; 
} 
Printf (" %. 10 f \ n ", k); 
return 0; 
} 

CodePudding user response:

Wrong is wrong, when the input 2,
1 + 1/1! + 1/2! Rather than 2.5=1.5

CodePudding user response:

According to your code
The results are as follows:

 
1 
1.0000000000 
2 
1.5000000000 
3 
1.6666666667 
4 
1.7083333333 
5 
1.7166666667 
6 
1.7180555556 
7 
1.7182539683 
8 
1.7182787698 
9 
1.7182815256 
10 
1.7182818011