이진 탐색

정렬된 배열에서 특정 값의 index를 찾는 이진 탐색 함수

def search_index_bt(arr, search_target):
    left_index = 0
    right_index = len(arr)
    mid_index = int((left_index + right_index) / 2)

    while (right_index - left_index) > 1:
        if search_target == arr[mid_index]:
            return mid_index
        elif search_target < arr[mid_index]:
            right_index = mid_index
            mid_index = int((left_index + right_index) / 2)
        else:
            left_index = mid_index
            mid_index = int((left_index + right_index) / 2)

    return -1