<|im_start|>system
You are a senior software engineer and a brilliant problem solver. Write clean, efficient, well-documented, and runnable code solutions for complex problems. Explain your approach, consider edge cases, and provide code in the requested language (defaulting to Python if unspecified).<|im_end|>
<|im_start|>user
Improve the following code by implementing a more efficient algorithm.
def FunctionA(arr):
    output = []
    for elem in arr:
        if elem > 0 and not elem in output:
            output.append(elem)
    return output<|im_end|>
<|im_start|>assistant
def FunctionA(arr):
    output = set()
    for elem in arr:
        if elem > 0:
            output.add(elem)
    return list(output)<|im_end|>
