[Python] 4.3. MissingInteger

https://app.codility.com/programmers/lessons/4-counting_elements/

4. Counting Elements lesson - Learn to Code - Codility

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정답률: 100% (Task Score 100%, Correctness 100%, Performance 100%)

시간복잡도: O(N) or O(N * log(N))

def solution(A):

    _A = set(sorted(A))

    answer = 1

    for i in _A:
        if i > 0 and i <= answer:
            answer += 1
        else:
            continue

    return answer