Leetcode•Aug 16, 2025
Find K Closest Elements
Hazrat Ali
Leetcode
Given a sorted integer array arr, two integers k and x, return the k closest integers to x in the array. The result should also be sorted in ascending order.
An integer a is closer to x than an integer b if:
|a - x| < |b - x|, or|a - x| == |b - x|anda < b
Example 1:
Input: arr = [1,2,3,4,5], k = 4, x = 3
Output: [1,2,3,4]
Example 2:
Input: arr = [1,1,2,3,4,5], k = 4, x = -1
Output: [1,1,2,3]
Solution
/**
* @param {number[]} arr
* @param {number} k
* @param {number} x
* @return {number[]}
*/
const findClosestElements = (arr, k, x) => {
const p = findClosestElement(arr, x);
let i = p - 1;
let j = p;
while (k-- > 0) {
if (i < 0 || (j < arr.length && Math.abs(arr[j] - x) < Math.abs(arr[i] - x))) {
j++;
} else {
i--;
}
}
return arr.slice(i + 1, j);
};
const findClosestElement = (arr, x) => {
let lo = 0;
let hi = arr.length - 1;
while (lo <= hi) {
const mid = lo + Math.floor((hi - lo) / 2);
if (arr[mid] === x) {
return mid;
}
if (arr[mid] > x) {
hi = mid - 1;
} else {
lo = mid + 1;
}
}
return lo;
};