算法题：UVA 10534 Wavio Sequence（dp + LIS）

算法题：UVA 10534 Wavio Sequence（dp + LIS）2014-04-12 csdn博客 accelerator_Wavio is a sequence of integers. It has some interesting properties.

· Wavio is of odd length i.e. L = 2*n + 1.

· The first （n+1） integers of Wavio sequence makes a strictly increasing sequence.

· The last （n+1） integers of Wavio sequence makes a strictly decreasing sequence.

· No two adjacent integers are same in a Wavio sequence.

For example 1, 2, 3, 4, 5, 4, 3, 2, 0 is an Wavio sequence of length 9. But 1, 2, 3, 4, 5, 4, 3, 2, 2 is not a valid wavio sequence. In this problem, you will be given a sequence of integers. You have to find out the length of the longest Wavio sequence which is a subsequence of the given sequence. Consider, the given sequence as :

1 2 3 2 1 2 3 4 3 2 1 5 4 1 2 3 2 2 1.

Here the longest Wavio sequence is : 1 2 3 4 5 4 3 2 1. So, the output will be 9.

Input

The input file contains less than 75 test cases. The description of each test case is given below: Input is terminated by end of file.

Each set starts with a postive integer, N（1<=N<=10000）. In next few lines there will be N integers.

Output

For each set of input print the length of longest wavio sequence in a line.
Sample Input Output for Sample Input

Problemsetter: Md. Kamruzzaman, Member of Elite Problemsetters" Panel