Count days without meetings

Array Sorting

48.1% acceptance

Feb 24, 2026

779

You are given a positive integer days representing the total number of days an employee is available for work (starting from day 1). You are also given a 2D array meetings of size n where, meetings[i] = [start_i, end_i] represents the starting and ending days of meeting i (inclusive). Return the count of days when the employee is available for work but no meetings are scheduled. Note: The meetings may overlap.

Solution

Rust

Time O(n log n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn count_days(days: i32, mut meetings: Vec<Vec<i32>>) -> i32 {
    meetings.sort_unstable();
    let mut covered = 0i32;
    let mut cur_start = -1i32;
    let mut cur_end = -1i32;
    for m in &meetings {
      if m[0] > cur_end + 1 {
        if cur_end >= 0 {
          covered += cur_end - cur_start + 1;
        }
        cur_start = m[0];
        cur_end = m[1];
      } else {
        cur_end = cur_end.max(m[1]);
      }
    }
    if cur_end >= 0 {
      covered += cur_end - cur_start + 1;
    }
    days - covered
  }
}