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.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;

using System.IO;

class _Class
{
	void _(){
	}

	void _Do()
  {
    var N = _int();
		var a = _int();
		int l = 1;
		int? o=null;
		for (int i=0;i<a.Length;i++)
		{
			if (i==0)
			{

			}
			else
			{
				var o2 = Math.Sign(a[i] - a[i - 1]);
				if (
					o == 1 && o2 ==-1 || 
					o==-1&&o2==1)
				{
					o = 0;
					l++;
				}
				else if(o2!=0)
					o = o2;
			}
		}
		Console.WriteLine(l);
	}



	static void Main(string[] args)
  {
    new _Class()._Do();
  }

#region

  string _string()
  {
    return Console.ReadLine();
  }

	//
	string[] _strings()
  {
    return Console.ReadLine().Split();
  }

  int[] _int(int n)
  {
    var x = new int[n];
    for (var i = 0; i < n; i++)
    {
      x[i] = int.Parse(Console.ReadLine());
    }
    return x;
  }

	//
	int[] _int()
  {
    var ss = Console.ReadLine().Split();

    var x = new int[ss.Length];
    for (var i = 0; i < ss.Length; i++)
      x[i] = int.Parse(ss[i]);

    return x;
  }

	long[] _long()
	{
		var ss = Console.ReadLine().Split();

		var x = new long[ss.Length];
		for (var i = 0; i < ss.Length; i++)
			x[i] = long.Parse(ss[i]);

		return x;
	}
#endregion

}