Problem:
Score : 300 points

Problem Statement

You are given an array A of length N.
Your task is to divide it into several contiguous subarrays.
Here, all subarrays obtained must be sorted in either non-decreasing or non-increasing order.
At least how many subarrays do you need to divide A into?

Constraints

1 \leq N \leq 10^5

1 \leq A_i \leq 10^9

Each A_i is an integer.

Input

Input is given from Standard Input in the following format:

N
A_1 A_2 ... A_N

Output

Print the minimum possible number of subarrays after division of A.

Sample Input 1

6
1 2 3 2 2 1

Sample Output 1

2

One optimal solution is to divide the array into [1,2,3] and [2,2,1].

Sample Input 2

9
1 2 1 2 1 2 1 2 1

Sample Output 2

5

Sample Input 3

7
1 2 3 2 1 999999999 1000000000

Sample Output 3

3

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;

public class Main {
	private static Scanner sc = new Scanner(System.in);
	public static void main(String[] args) {
		int n = sc.nextInt();
		int[] a = new int[100010];
		a[0] = sc.nextInt();
		int c = 1;
		for (int i = 1;i < n;i++) {
			int tmp = sc.nextInt();
			if (a[c-1]==tmp) continue;
			a[c++] = tmp;
		}
		List<Integer> l = new ArrayList<>();
		c = 0;
		int ret = 0;
		while (true) {
			int tmp = a[c++];
			if (tmp==0) {
				ret++;
				break;
			}
			l.add(tmp);
			if (l.size()<=2) continue;
			if (i(l)||d(l)) {
				l.remove(0);
				continue;
			} else {
				l.clear();
				l.add(tmp);
				ret++;
			}
		}
		System.out.println(ret);
	}

	private static boolean i(List<Integer> l) {
		for (int i = 1;i < l.size();i++) {
			if (l.get(i-1)>l.get(i)) return false;
		}
		return true;
	}
	private static boolean d(List<Integer> l) {
		for (int i = 1;i < l.size();i++) {
			if (l.get(i-1)<l.get(i)) return false;
		}
		return true;
	}
}