#luoguP10490. Missile Defence System

    ID: 14912 远端评测题 2000ms 512MiB 尝试: 0 已通过: 0 难度: 5 上传者: 标签>搜索O2优化深度优先搜索 DFS剪枝

Missile Defence System

题目描述

To play against the threats of malicious countries nearby, Country R has updated their missile defence system. The new type system can bring down a series of missiles as long as they are coming in ascending order by altitude or descending order by altitude.

Given the heights of a sequence of coming missiles, the general wants to know how many sets of the new type systems are needed to bring down all of them.

输入格式

The input consists of several test cases. The first line of each test case contains an integer n(1n50)n (1 \le n \le 50). The next line contains n different integers indicating the heights.

输出格式

For each test case output a single line containing the number of systems needed.For each test case output a single line containing the number of systems needed.

5 
3 5 2 4 1 
0
2

提示

Two sets of systems are needed for the sample. One brings down 3, 4 and the other brings down 5, 2, 1.