feat.thanos search

binary_search.py

from typing import *
import pytest


def solution(arr: list, target: int) -> int:
    start_idx = 0
    end_idx = len(arr)
    while 1:
        mid_idx = (start_idx + end_idx) // 2
        mid_value = arr[mid_idx]
        # 앞 뒤 인덱스 더하고 가운데 인덱스의 값 리턴
        if mid_value > target:
            end_idx = mid_idx
        elif end_idx - start_idx == 1:
            if mid_value == target:
                return mid_idx
            else:
                return -1
        else:
            start_idx = mid_idx


def test_solution():
    arr = [1, 3, 5, 8, 17, 60, 70]
    arr2 = [2, 4]
    assert solution(arr, 60) == 5
    assert solution(arr, 1) == 0
    assert solution(arr, 8) == 3
    assert solution(arr, 17) == 4
    assert solution(arr, 70) == 6
    assert solution(arr2, 4) == 1
    assert solution(arr2, 2) == 0
    assert solution(arr2, 100) == -1


if __name__ == '__main__':
    pytest.main()