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.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
class Program
{
    public static int ans;
    public static int n;
    public static int[] a;
    static void Main(string[] args)
    {
        ans = 1;
        n = int.Parse(Console.ReadLine());
        a = Console.ReadLine().Split().Select(int.Parse).ToArray();
        int[] b=new int[n-1];
        int way = 1;
        for (int i = 0; i < n-1; i++)
        {
            if (a[i] < a[i + 1]) b[i] = 0;
            if (a[i] == a[i + 1]) b[i] = 1;
            if (a[i] > a[i + 1]) b[i] = 2;
        }
        for (int j = 0; j < n-2; j++)
        {
            if (b[j] == 0) { way = 0; }
            if (b[j] == 2) { way = 2; }
            if (way == 1) { continue; }
            if ((way + 2 == b[j + 1] || way == b[j + 1] + 2))
            {
                ans++;
                way = 2 - way;
                j++;
            }
        }
        
        Console.WriteLine(ans.ToString());
        Console.ReadLine();
    }
    
}