How do you solve Find Closest Number to Zero on LeetCode?

Find Closest Number to Zero (LeetCode #2239) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(n) time complexity and O(1) space complexity. Key insight: The absolute value is crucial when determining proximity to zero.

What is the brute force solution for Find Closest Number to Zero?

The brute force approach for Find Closest Number to Zero is Brute Force, with O(n) time complexity and O(1) space complexity. The brute force approach involves checking each number in the array to find the one closest to zero. This is straightforward but inefficient, especially for larger arrays. The optimal Optimal Solution approach improves this to O(n).

What algorithm or data structure is used to solve Find Closest Number to Zero?

Find Closest Number to Zero uses the following concepts: Array. The recommended patterns to study are: Array, Two Pointers.

What are the interview tips for Find Closest Number to Zero?

Always clarify the problem statement and constraints before jumping into coding. Think out loud during the interview to show your thought process. Consider edge cases, such as arrays with only one element or all elements being the same.

What are common mistakes when solving Find Closest Number to Zero?

Forgetting to check both the absolute value and the actual value when there's a tie. Not initializing the closest variable correctly, which can lead to incorrect results.

#2239

Find Closest Number to Zero

Easy

ArrayArrayTwo Pointers

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

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

💡

Intuition

Time O(n)Space O(1)

The optimal solution is similar to the brute force approach but focuses on maintaining the closest number more efficiently in a single pass through the array.

⚙️

Algorithm

5 steps

1Step 1: Initialize a variable to keep track of the closest number to zero.
2Step 2: Loop through each number in the array.
3Step 3: For each number, check if its absolute value is less than the current closest number's absolute value.
4Step 4: If they are equal, choose the larger number.
5Step 5: Update the closest number if necessary and return it after the loop.

solution.py11 lines

1# Full working Python code
2
3def findClosestNumber(nums):
4    closest = nums[0]
5    for num in nums:
6        if abs(num) < abs(closest) or (abs(num) == abs(closest) and num > closest):
7            closest = num
8    return closest
9
10# Example usage
11print(findClosestNumber([-4,-2,1,4,8]))  # Output: 1

ℹ

Complexity note: The time complexity remains O(n) as we still traverse the array once, and the space complexity is O(1) since we only use a constant amount of extra space.

1The absolute value is crucial when determining proximity to zero.
2When two numbers are equally close to zero, the larger number should be preferred.

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