n passengers board an airplane with exactly n seats. The first passenger has lost the ticket and picks a seat randomly. But after that, the rest of the passengers will:
- Take their own seat if it is still available, and
- Pick other seats randomly when they find their seat occupied
Return the probability that thenthperson gets his own seat.
Input: n = 1 Output: 1.00000 Explanation: The first person can only get the first seat.
Input: n = 2 Output: 0.50000 Explanation: The second person has a probability of 0.5 to get the second seat (when first person gets the first seat).
1 <= n <= 105
implSolution{pubfnnth_person_gets_nth_seat(n:i32) -> f64{match n {1 => 1.0, _ => 0.5,}}}