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;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            long n = long.Parse(Console.ReadLine());
            long[] a = Console.ReadLine().Split(' ').Select(e => long.Parse(e)).ToArray();
            long cnt = 0;
            long subCnt = 0;
            long status = 0;
            for (int i = 0; i < n; i++)
            {
                if(subCnt == 0)
                {
                    subCnt++;
                    cnt++;
                    continue;
                }
                if (subCnt == 1)
                {
                    status = a[i] - a[i - 1];
                    subCnt++;
                    continue;
                }
                if (subCnt > 1)
                {
                    if (status == 0)
                    {
                        subCnt++;
                        status = a[i] - a[i - 1];
                        continue;
                    }
                    if (status>0 && a[i] -a[i-1]<0)
                    {
                        subCnt = 0;
                        status = 0;
                        i--;
                        continue;
                    }
                    if (status < 0 && a[i] - a[i - 1] > 0)
                    {
                        subCnt = 0;
                        status = 0;
                        i--;
                        continue;
                    }
                    if (status > 0 && a[i] - a[i - 1] >= 0)
                    {
                        subCnt++;
                        status = a[i] - a[i - 1];
                        continue;
                    }
                    if (status < 0 && a[i] - a[i - 1] <= 0)
                    {
                        subCnt++;
                        status = a[i] - a[i - 1];
                        continue;
                    }
                }
            }

            Console.WriteLine(cnt);
        }
    }
}