Phone number prefix

Array String Trie Sorting

70.5% acceptance

Mar 31, 2026

You are given a string array numbers that represents phone numbers. Return true if no phone number is a prefix of any other phone number; otherwise, return false.

Solution

Rust

Time O(n log n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn phone_prefix(numbers: Vec<String>) -> bool {
    let mut sorted = numbers;
    sorted.sort();
    for i in 0..sorted.len() - 1 {
      if sorted[i + 1].starts_with(&sorted[i]) {
        return false;
      }
    }
    true
  }
}