PilingUp.py

"""
Title     : Piling Up!
Subdomain : Collections
Domain    : Python
Author    : Ahmedur Rahman Shovon
Created   : 15 July 2016
Problem   : https://www.hackerrank.com/challenges/piling-up/problem
"""

from collections import deque

cas = int(input())
for _ in range(cas):
    n = int(input())
    dq = deque(map(int, input().split()))
    possible = True
    element = (2**31) + 1
    while dq:
        left_element = dq[0]
        right_element = dq[-1]
        if left_element >= right_element and element >= left_element:
            element = dq.popleft()
        elif right_element >= left_element and element >= right_element:
            element = dq.pop()
        else:
            possible = False
            break
    if possible:
        print("Yes")
    else:
        print("No")