#2997

Minimum Number of Operations to Make Array XOR Equal to K

Medium
ArrayBit ManipulationBit ManipulationXOR properties
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Approaches

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

Intuition

Time O(n)Space O(1)

The optimal solution focuses on calculating the difference between the initial XOR and k. Each differing bit indicates a necessary flip. This approach is efficient because it directly counts the required flips without exploring all combinations.

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Algorithm

3 steps
  1. 1Step 1: Calculate the initial XOR of all elements in the array.
  2. 2Step 2: Calculate the XOR difference between the initial XOR and k.
  3. 3Step 3: Count the number of differing bits in the XOR difference, which gives the minimum number of flips required.
solution.py9 lines
1# Full working Python code
2
3def min_operations_optimal(nums, k):
4    initial_xor = 0
5    for num in nums:
6        initial_xor ^= num
7    xor_diff = initial_xor ^ k
8    return bin(xor_diff).count('1')
9

Complexity note: The complexity is O(n) because we only make a single pass through the array to calculate the initial XOR and then a constant time operation to count the differing bits.

  • 1The XOR operation is reversible and can be used to determine the bits that need to be flipped.
  • 2Each differing bit between the initial XOR and k directly corresponds to a necessary flip.

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