Partition Array into Two Non-Decreasing Subarrays

You are given an array of n integers. Your task is to determine whether it is possible to partition the array into two contiguous subarrays such that each subarray is non-decreasing (i.e., each element is not less than the previous one).

Formally, given an integer n and an array \(A = [a_1, a_2, \dots, a_n]\), find an index \(i\) with \(1 \le i \le n-1\) such that:

[ \begin{aligned} a_1 &\le a_2 \le \dots \le a_i, \ a_{i+1} &\le a_{i+2} \le \dots \le a_n. \end{aligned} ]

If such an index exists, output YES, otherwise output NO. Note that an array with a single element cannot be partitioned.

inputFormat

The input is given via standard input (stdin) and consists of two lines:

1. The first line contains an integer n representing the number of elements in the array.
2. The second line contains n space-separated integers which represent the elements of the array.

outputFormat

Output a single line to standard output (stdout) containing either YES if the array can be partitioned into two non-decreasing contiguous subarrays, or NO otherwise.

5
2 2 3 1 4

YES