Find k closest elements

Array Two Pointers Binary Search Sliding Window Sorting Heap (Priority Queue)

49.4% acceptance

Feb 20, 2026

9008

907

Given a sorted integer array arr and two integers k and x, return the k closest integers to x in the array. Result should be sorted in ascending order. If two integers are equally close, choose the smaller one.

Solution

Rust

Time O(n log n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn find_closest_elements(arr: Vec<i32>, k: i32, x: i32) -> Vec<i32> {
    let k = k as usize;
    let n = arr.len();
    let mut lo = 0usize;
    let mut hi = n - k;
    while lo < hi {
      let mid = (lo + hi) / 2;
      if x - arr[mid] > arr[mid + k] - x {
        lo = mid + 1;
      } else {
        hi = mid;
      }
    }
    arr[lo..lo + k].to_vec()
  }
}