#2817

Minimum Absolute Difference Between Elements With Constraint

Medium
ArrayBinary SearchOrdered SetHash MapArray
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Approaches

Brute ForceOptimal
Complexity Comparison
Brute ForceOptimal Solution
Time
O(n²)
O(n log n)
Space
O(1)
O(n)
💡

Intuition

Time O(n log n)Space O(n)

Using a sorted data structure allows us to efficiently find the closest values to each element while maintaining the index constraint. This reduces the time complexity significantly.

⚙️

Algorithm

4 steps
  1. 1Step 1: Initialize a sorted list to keep track of elements seen so far.
  2. 2Step 2: Iterate through the array, and for each element nums[j], check the sorted list for the closest elements.
  3. 3Step 3: For each nums[j], calculate the absolute difference with the closest elements in the sorted list, ensuring they are at least x indices apart.
  4. 4Step 4: Add nums[j] to the sorted list for future comparisons.
solution.py16 lines
1# Full working Python code
2from sortedcontainers import SortedList
3
4def minAbsDifference(nums, x):
5    sorted_list = SortedList()
6    min_diff = float('inf')
7    for j in range(len(nums)):
8        if j >= x:
9            sorted_list.add(nums[j - x])
10        if sorted_list:
11            pos = sorted_list.bisect_left(nums[j])
12            if pos < len(sorted_list):
13                min_diff = min(min_diff, abs(sorted_list[pos] - nums[j]))
14            if pos > 0:
15                min_diff = min(min_diff, abs(sorted_list[pos - 1] - nums[j]))
16    return min_diff

Complexity note: The complexity arises from maintaining a sorted list of elements, where each insertion and search operation takes logarithmic time.

  • 1The problem requires careful consideration of index constraints.
  • 2Using sorted data structures can significantly reduce the time complexity.

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