18 lines
338 B
C++
18 lines
338 B
C++
|
#include <bits/stdc++.h>
|
||
|
|
|
||
|
|
using namespace std;
|
||
|
|
|
||
|
|
int main() {
|
||
|
|
int n;
|
||
|
|
cin >> n;
|
||
|
|
double s = 0;
|
||
|
|
if (n % 2 == 0) {
|
||
|
|
for (int i = 2; i <= n; i = i + 2)
|
||
|
|
s += 1.0 / i;
|
||
|
|
} else {
|
||
|
|
for (int i = 1; i <= n; i = i + 2)
|
||
|
|
s += 1.0 / i;
|
||
|
|
}
|
||
|
|
cout << s << endl;
|
||
|
|
return 0;
|
||
|
|
}
|