README.md

1227. Airplane Seat Assignment Probability

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 the nth person gets his own seat.

Example 1:

Input: n = 1
Output: 1.00000
Explanation: The first person can only get the first seat.

Example 2:

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).

Constraints:

• 1 <= n <= 105

Solutions (Rust)

1. Solution

impl Solution {
    pub fn nth_person_gets_nth_seat(n: i32) -> f64 {
        match n {
            1 => 1.0,
            _ => 0.5,
        }
    }
}