题目描述
Problem Statement
Let N be a positive odd number.
A sequence of integers of length $N, S = (S_1, S_2, \dots, S_N)$, is said to be M-type if "for each even number $i = 2, 4, \dots, N - 1$, it holds that S_{i-1} < S_i and S_i > S_{i+1}".
You are given a sequence of positive integers of length $N, A = (A_1, A_2, \dots, A_N)$.
Determine if it is possible to rearrange A to be M-type.
Input
The input is given from Standard Input in the following format:
N
A_1 \ A_2 \ $\dots$ \ A_N
Output
If it is possible to rearrange the given integer sequence A to be M-type, print Yes; otherwise, print No.
Constraints
- $1 \leq N \leq 2 \times 10^5$
- N is an odd number.
- $1 \leq A_i \leq 10^9$ \ \ $(1 \leq i \leq N)$
Sample Input 1
5
1 2 3 4 5
Sample Output 1
Yes
The given sequence is A = (1, 2, 3, 4, 5).
After rearranging it, for example, to B = (4, 5, 1, 3, 2),
- for i = 2, it holds that B_1 = 4 < 5 = B_2 and B_2 = 5 > 1 = B_3;
- for i = 4, it holds that B_3 = 1 < 3 = B_4 and B_4 = 3 > 2 = B_5.
Therefore, this sequence B is M-type, and the answer is Yes.
Sample Input 2
5
1 6 1 6 1
Sample Output 2
Yes
The given sequence A itself is M-type.
Sample Input 3
5
1 6 6 6 1
Sample Output 3
No
It is impossible to rearrange it to be M-type.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分