#3190

Find Minimum Operations to Make All Elements Divisible by Three

Easy
ArrayMathMathArray
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Approaches

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

Intuition

Time O(n)Space O(1)

The optimal solution leverages the fact that each number can be adjusted to the nearest multiple of 3 in at most one operation. By calculating the necessary adjustments directly, we can achieve the result more efficiently.

⚙️

Algorithm

3 steps
  1. 1Step 1: Initialize a counter for operations to 0.
  2. 2Step 2: For each element in the array, calculate the remainder when divided by 3.
  3. 3Step 3: If the remainder is not zero, add the minimum of the remainder and (3 - remainder) to the operations counter.
solution.py2 lines
1def min_operations(nums):
2    return sum(min(num % 3, 3 - (num % 3)) for num in nums)

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

  • 1Each number can be adjusted to a multiple of 3 in at most one operation.
  • 2Understanding the modulo operation helps in determining the necessary adjustments.

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