How do you solve Smallest Absent Positive Greater Than Average on LeetCode?

Smallest Absent Positive Greater Than Average (LeetCode #3678) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(n) time complexity and O(n) space complexity. Key insight: Using a set allows for faster lookups.

What is the time complexity of Smallest Absent Positive Greater Than Average?

The optimal solution for Smallest Absent Positive Greater Than Average runs in O(n) time and uses O(n) space. The complexity is linear due to the single pass to create the set and another pass to find the absent integer.

What is the brute force solution for Smallest Absent Positive Greater Than Average?

The brute force approach for Smallest Absent Positive Greater Than Average is Brute Force, with O(n²) time complexity and O(1) space complexity. Calculate the average and start checking integers one by one until you find the smallest absent positive integer greater than the average. The optimal Optimal Solution approach improves this to O(n).

What algorithm or data structure is used to solve Smallest Absent Positive Greater Than Average?

Smallest Absent Positive Greater Than Average uses the following concepts: Array, Hash Table. The recommended patterns to study are: Hash Map, Array.

What are the interview tips for Smallest Absent Positive Greater Than Average?

Explain your thought process clearly. Consider edge cases like all negative numbers. Discuss time and space complexity.

What are common mistakes when solving Smallest Absent Positive Greater Than Average?

Not considering negative numbers in the array. Forgetting to check strictly greater than the average.

#3678

Smallest Absent Positive Greater Than Average

Easy

ArrayHash TableHash MapArray

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

	Brute Force	Optimal Solution★
Time	O(n²)	O(n)
Space	O(1)	O(n)

💡

Intuition

Time O(n)Space O(n)

Use a set to track existing numbers for quick lookup, then find the smallest absent positive integer greater than the average.

⚙️

Algorithm

3 steps

1Step 1: Calculate the average of nums.
2Step 2: Store all positive integers in a set for O(1) lookup.
3Step 3: Start from floor(avg) + 1 and find the first integer not in the set.

solution.py7 lines

1def smallestAbsent(nums):
2    avg = sum(nums) / len(nums)
3    num_set = set(nums)
4    x = int(avg) + 1
5    while x in num_set:
6        x += 1
7    return x

ℹ

Complexity note: The complexity is linear due to the single pass to create the set and another pass to find the absent integer.

1Using a set allows for faster lookups.
2The average helps to limit the search space for the absent integer.

Solutions and explanations are original Tejav content. Problem titles © LeetCode — use the LeetCode button above for the full problem statement.