374. Check if Linked List is Sorted

Given a linked list, determine whether it is sorted. Return "ascending" if it is non-decreasing, "descending" if it is non-increasing, "both" if it is constant (or has 0/1 nodes), and "neither" otherwise.

Input: An array of node values.

Output: Quoted string — one of ascending/descending/both/neither.

Examples

Input: [1,2,3,4]
Output: "ascending"
Explanation: Non-decreasing.

Input: [4,3,2,1]
Output: "descending"
Explanation: Non-increasing.

Input: [5,5,5]
Output: "both"
Explanation: Constant counts as both.

Constraints

• 0<=n<=10^5
• -10^9<=value<=10^9

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