Kth distinct string in an array

Array Hash Table String Counting

82.1% acceptance

Feb 25, 2026

1313

A distinct string is a string that is present only once in an array. Given an array of strings arr, and an integer k, return the kth distinct string present in arr. If there are fewer than k distinct strings, return an empty string "". Note that the strings are considered in the order in which they appear in the array.

Solution

Rust

Time O(n)

Space O(n)

LeetCode

solution.rs

impl Solution {
  pub fn kth_distinct(arr: Vec<String>, k: i32) -> String {
    use std::collections::HashMap;
    let mut count: HashMap<&str, usize> = HashMap::new();
    for s in &arr {
      *count.entry(s.as_str()).or_insert(0) += 1;
    }
    let mut cnt = 0;
    for s in &arr {
      if count[s.as_str()] == 1 {
        cnt += 1;
        if cnt == k {
          return s.clone();
        }
      }
    }
    String::new()
  }
}