How do you solve Form Smallest Number From Two Digit Arrays on LeetCode?

Form Smallest Number From Two Digit Arrays (LeetCode #2605) 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 smallest number can be formed by either a single digit or a combination of two digits.

What is the time complexity of Form Smallest Number From Two Digit Arrays?

The optimal solution for Form Smallest Number From Two Digit Arrays runs in O(n) time and uses O(1) space. This solution is linear because we only need to find the minimum values from both arrays, which can be done in a single pass each.

What is the brute force solution for Form Smallest Number From Two Digit Arrays?

The brute force approach for Form Smallest Number From Two Digit Arrays is Brute Force, with O(n²) time complexity and O(1) space complexity. We can generate all possible combinations of digits from both arrays and then find the smallest valid number. This approach is straightforward but may not be efficient for larger inputs. The optimal Optimal Solution approach improves this to O(n).

What algorithm or data structure is used to solve Form Smallest Number From Two Digit Arrays?

Form Smallest Number From Two Digit Arrays uses the following concepts: Array, Hash Table, Enumeration. The recommended patterns to study are: Hash Map, Array.

What are the interview tips for Form Smallest Number From Two Digit Arrays?

Always think about edge cases, like when both arrays have the same digit. Discuss your thought process and approach before jumping into coding. Consider both brute force and optimal solutions during interviews to showcase your understanding.

What are common mistakes when solving Form Smallest Number From Two Digit Arrays?

Not considering the case where both arrays have the same minimum digit. Overlooking the need to check combinations when the minimum digits differ.

#2605

Form Smallest Number From Two Digit Arrays

Easy

ArrayHash TableEnumerationHash MapArray

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

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

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Intuition

Time O(n)Space O(1)

Instead of generating all combinations, we can find the minimum digit in both arrays and check if they are the same. If they are, we return that digit. If not, we can combine the smallest digits from each array to form the smallest two-digit number.

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Algorithm

3 steps

1Step 1: Find the minimum digit in nums1 and nums2.
2Step 2: If the minimum digits are the same, return that digit.
3Step 3: If they are different, return the combination of the two smallest digits in ascending order.

solution.py7 lines

1def smallestNumber(nums1, nums2):
2    min1 = min(nums1)
3    min2 = min(nums2)
4    if min1 == min2:
5        return min1
6    return min(min1 * 10 + min2, min2 * 10 + min1)
7

ℹ

Complexity note: This solution is linear because we only need to find the minimum values from both arrays, which can be done in a single pass each.

1The smallest number can be formed by either a single digit or a combination of two digits.
2Finding the minimum digits in both arrays is crucial for optimizing the solution.

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