第二题 t = int(input()) for _ in range(t):     n = int(input())     nums = list(map(int, input().split()))     def dfs(nums):         if len(nums) <= 1:             return True         root = nums[0]         left = []         right = []         for num in nums[1:]:             if num > root:                 right.append(num)             else:                 left.append(num)         Abs = abs(get_left([root]+left) - get_right([root]+right))         return dfs(left) and dfs(right) and Abs < ban     def get_left(nums):         c = 0         tmp = nums[0]         for num in nums[1:]:             if num<tmp:                 c += 1                 tmp = num         return c     def get_right(nums):         c = 0         tmp = nums[0]         for num in nums[1:]:             if num>tmp:                 c += 1                 tmp = num         return c     ban = min(11, n//2)     if dfs(nums):         print("YES")     else:         print("NO")