#2009

Minimum Number of Operations to Make Array Continuous

Hard
ArrayHash TableBinary SearchSliding WindowHash MapArray
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Approaches

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

Intuition

Time O(n log n)Space O(n)

The optimal solution uses sorting and a sliding window approach to efficiently find the minimum number of operations needed. By focusing on the range of unique elements, we can minimize replacements.

⚙️

Algorithm

3 steps
  1. 1Step 1: Sort the input array to arrange the numbers in increasing order.
  2. 2Step 2: Use a sliding window to find the longest continuous segment of unique numbers that can fit the criteria.
  3. 3Step 3: Calculate the number of operations needed as the difference between the total length and the length of the longest valid segment.
solution.py13 lines
1# Full working Python code
2
3def min_operations(nums):
4    nums = sorted(set(nums))  # Remove duplicates and sort
5    n = len(nums)
6    left = 0
7    min_operations = float('inf')
8    for right in range(n):
9        while nums[right] - nums[left] >= n:
10            left += 1
11        min_operations = min(min_operations, n - (right - left + 1))
12    return min_operations
13

Complexity note: The sorting step takes O(n log n), and the sliding window runs in O(n), making this approach efficient for large inputs.

  • 1Sorting the array helps in easily identifying the range of unique numbers.
  • 2Using a sliding window allows us to efficiently find the longest valid segment without unnecessary checks.

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