二分查找

def solve():
    nums = [-1, 0, 3, 5, 9, 12]
    target = 9
    left, right = 0, len(nums) - 1
    result = -1
    while left <= right:
        mid = (left + right) // 2
        if nums[mid] == target:
            result = mid
            break
        elif nums[mid] < target:
            left = mid + 1
        else:
            right = mid - 1
    print(result)