There is a horizontal row of N cubes. The length of each cube is given. You need to create a new vertical pile of cubes. The new pile should follow these directions: if is on top of then .
When stacking the cubes, you can only pick up either the leftmost or the rightmost cube each time. Print "Yes" if it is possible to stack the cubes. Otherwise, print "No". Do not print the quotation marks.
The first line contains a single integer , the number of test cases.
For each test case, there are lines.
The first line of each test case contains , the number of cubes.
The second line contains space separated integers, denoting the sideLengths of each cube in that order.
For each test case, output a single line containing either "Yes" or "No" without the quotes.
2 6 4 3 2 1 3 4 3 1 3 2
In the first test case, pick in this order: left - , right - , left - , right - , left - , right - .
In the second test case, no order gives an appropriate arrangement of vertical cubes. will always come after either or .
Solution in Python
from collections import deque def check(d): while d: big = d.popleft() if d>d[-1] else d.pop() if not d: return "Yes" if d[-1]>big or d>big: return "No" for i in range(int(input())): int(input()) d = deque(map(int,input().split())) print(check(d))