Transform array to sorted array

Question

Given an unsorted array of integers, write a function that transforms the array into a sorted array in ascending order. The function should take the array as input and return a new array containing the sorted elements. Ensure that your solution is efficient and handles edge cases, such as empty arrays or arrays with duplicate values.

Codemia · Accepted Answer

The problem requires transforming an unsorted array of integers into a sorted array. The underlying pattern here is sorting, which can be efficiently tackled using various sorting algorithms. Given the problem constraints and the need for efficiency, we will consider algorithms like Quick Sort, Merge Sort, or even Timsort (used in Python's built-in sort). The reason these patterns apply is due to their average-case time complexity of O(n log n), making them suitable for larger datasets as opposed to simpler algorithms like Bubble Sort or Insertion Sort, which have O(n^2) time complexity.

1. **Choose the Sorting Algorithm**: We will use Python’s built-in `sorted()` function, which implements Timsort. 
2. **Handle Edge Cases**: Before sorting, check if the input array is empty. If it is, return an empty array immediately. 
3. **Sorting Logic**: By invoking the `sorted()` function on the array, we ensure that the function returns a new sorted array. 
4. **Return the Result**: Finally, return the sorted array.

**Example**: For an input array `[3, 1, 4, 1, 5]`, using `sorted()` will yield `[1, 1, 3, 4, 5]`.

Here is the Python solution implementing the discussed approach:
```python
def transform_to_sorted_array(arr):
    # Edge case: if the input array is empty
    if not arr:
        return []
    # Sorting the array using Python's built-in sorted function
    return sorted(arr)
```

The time complexity of the solution is O(n log n), where n is the number of elements in the array. This is due to the sorting algorithm (Timsort) used by Python’s `sorted()` function, which performs well on average. The space complexity is O(n) since Timsort requires additional space proportional to the size of the input array for merging operations. This is efficient given that we need to create a new sorted array.

1. **Empty Array**: If the input is `[]`, the function should return `[]`.  
2. **Array with Duplicates**: For an input like `[5, 3, 3, 2]`, the output should be `[2, 3, 3, 5]`.  
3. **Single Element Array**: If the input is `[42]`, the return value should be `[42]`.  
4. **Already Sorted Array**: If the input is `[1, 2, 3, 4]`, the function should still return `[1, 2, 3, 4]` without any change.

Transform array to sorted array

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