Library late fee calculator

Array Simulation

94.3% acceptance

Mar 31, 2026

You are given an integer array daysLate where daysLate[i] indicates how many days late the ith book was returned. The penalty is calculated as follows: If daysLate[i] == 1, penalty is 1. If 2 <= daysLate[i] <= 5, penalty is 2 * daysLate[i]. If daysLate[i] > 5, penalty is 3 * daysLate[i]. Return the total penalty for all books.

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn late_fee(days_late: Vec<i32>) -> i32 {
    days_late.iter().map(|&d| {
      if d == 1 { 1 }
      else if d >= 2 && d <= 5 { 2 * d }
      else { 3 * d }
    }).sum()
  }
}