二分查找

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