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: Wrong Answer)

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

class P
{
    static void Main()
    {
        int n = int.Parse(Console.ReadLine());
        int[] a = new int[n];
        string[] _ = Console.ReadLine().Split(' ');
        int ans = 1;
        int d = 1;
        int c = 1;
        if (1 < n)
        {
            a[0] = int.Parse(_[0]);
            a[1] = int.Parse(_[1]);
            if (a[0] <= a[1])
            {
                d = 1;
            }
            else
            {
                d = -1;
            }
        }
        for (int i = 2; i < n; i++)
        {
            a[i] = int.Parse(_[i]);
            if (c == 0)
            {
                c++;
            }
            else
            {
                if (d == 1)
                {
                    if (a[i - 1] <= a[i])
                    {
                        c++;
                    }
                    else
                    {
                        if (c > 0)
                        {
                            ans++;
                            d = -1;
                            c = 0;
                        }
                        else
                        {
                            c++;
                        }
                    }
                }
                else if (d == -1)
                {
                    if (a[i - 1] >= a[i])
                    {
                        c++;
                    }
                    else
                    {
                        if (c > 0)
                        {
                            ans++;
                            d = 1;
                            c = 0;
                        }
                        else
                        {
                            c++;
                        }
                    }
                }

            }
        }
        if (c == 0)
        {
            ans++;
        }
        Console.WriteLine(ans);
    }
}