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.io.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

class Main {
	public static void main(String[] args) throws IOException {
		Scanner in = new Scanner(System.in);

		int N = in.nextInt();
		int prev = 0;
		int diff = 0;
		boolean first = true;
		int ans = 1;
		for(int i=0;i<N;i++) {
			int d = in.nextInt();
			if(first) {
				prev = d;
				first = false;
				diff = 0;
				continue;
			}
			// 単調増加していたのに減った
			if(diff > 0 && !(d >= prev)) {
				ans += 1;
				diff = 0;
				prev = d;
				continue;
			}
			if(diff < 0 && !(d <= prev)) {
				ans += 1;
				diff = 0;
				prev = d;
				continue;
			}
			diff = d - prev;
			prev = d;
		}
		System.out.println(ans);
	}
}