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: Wrong Answer)

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long[] a = new long[n];
		for(int i=0;i<n;i++) a[i] = sc.nextLong();
		sc.close();

		int count1 = 0;
		for(int i=2;i<n;i++){
			if((a[i]-a[i-1])*(a[i-1]-a[i-2])<0){
				count1 ++;
				i ++;
			}
		}
		long[] b = new long[n];
		int count2 = 0;
		for(int i=0;i<n;i++) b[i] = a[n-1-i];
		for(int i=0;i<n;i++) a[i] = b[i];
		for(int i=2;i<n;i++){
			if((a[i]-a[i-1])*(a[i-1]-a[i-2])<0){
				count2 ++;
				i ++;
			}
		}
		System.out.println(Math.min(count1, count2)+1);

	}

}