Longest continuous subarray with absolute diff less than or equal to limit

Array Queue Sliding Window Heap (Priority Queue) Ordered Set Monotonic Queue

57.4% acceptance

Feb 25, 2026

4487

226

Given an array of integers nums and an integer limit, return the size of the longest non-empty subarray such that the absolute difference between any two elements of this subarray is less than or equal to limit.

Solution

Rust

Time O(n²)

Space O(n)

LeetCode

solution.rs

use std::collections::VecDeque;
impl Solution {
  pub fn longest_subarray(nums: Vec<i32>, limit: i32) -> i32 {
    let mut max_dq: VecDeque<usize> = VecDeque::new(); // decreasing
    let mut min_dq: VecDeque<usize> = VecDeque::new(); // increasing
    let mut left = 0;
    let mut result = 0;
    for right in 0..nums.len() {
      while !max_dq.is_empty() && nums[*max_dq.back().unwrap()] <= nums[right] {
        max_dq.pop_back();
      }
      max_dq.push_back(right);
      while !min_dq.is_empty() && nums[*min_dq.back().unwrap()] >= nums[right] {
        min_dq.pop_back();
      }
      min_dq.push_back(right);
      while nums[*max_dq.front().unwrap()] - nums[*min_dq.front().unwrap()] > limit {
        left += 1;
        if *max_dq.front().unwrap() < left { max_dq.pop_front(); }
        if *min_dq.front().unwrap() < left { min_dq.pop_front(); }
      }
      result = result.max(right - left + 1);
    }
    result as i32
  }
}