[Python] 이진탐색 구현

반복문

n, target = map(int, input().split())
array = list(map(int, input().split()))

def binary_search(array, target, start, end):
    while start <= end:
        mid = (start + end) // 2
        # 원하는 값을 찾았을 때
        if array[mid] == target:
            return mid
        # 더 작은 값을 찾아야 할 때
        elif array[mid] > target:
            end = mid - 1
        # 더 큰 값을 찾아야 할 때
        else:
            start = mid + 1
    return None

result = binary_search(array,target,0,n - 1)
if result == None:
    print('원소가 존재하지 않습니다')
else:
    print(result + 1)

재귀

n, target = map(int, input().split())
array = list(map(int, input().split()))

def binary_search(array, target, start, end):
    if start > end:
        return None
    mid = (start + end) // 2
    if array[mid] == target:
        return mid
    elif array[mid] > target:
        return(binary_search(array, target, start, mid - 1))
    else:
        return(binary_search(array, target, mid + 1, end))


result = binary_search(array,target,0,n - 1)
if result == None:
    print('원소가 존재하지 않습니다')
else:
    print(result + 1)