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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Linq;
using System.Collections.Generic;

public class Program
{
    public static void Main()
    {
        var n = int.Parse(Console.ReadLine());
        var xs = Console.ReadLine().Split()
            .Select(x => int.Parse(x))
            .ToArray();

        int count = 1;
        int sign = 0;
        for (int i = 1; i < n; ++i)
        {
            if (sign == 0 && i + 1 < n)
            {
                sign = Math.Sign(xs[i] - xs[i - 1]);
            }
            else if (sign > 0 && xs[i] - xs[i - 1] < 0 
            ||       sign < 0 && xs[i] - xs[i - 1] > 0)
            {
                ++count;
                sign = 0;
            }
        }

        Console.WriteLine(count);
    }
}