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;

class Program {
  enum Status {
    SAME, UP, DOWN
  }
  static void Main(string[] args)	{
    int N = int.Parse(Console.ReadLine());
    string[] val = Console.ReadLine().Split();
    int[] A = new int[N];
    for (int i = 0; i < N; ++i) {
      A[i] = int.Parse(val[i]);
    }

    Status status = Status.SAME;
    int cur = A[0];
    int count = 1;

    for (int i = 1; i < A.Length; ++i) {
      if (status == Status.SAME && cur != A[i]) {
        status = cur < A[i] ? Status.UP : Status.DOWN;
      }
      else if ((status == Status.UP && cur > A[i]) ||
      (status == Status.DOWN && cur < A[i])) {
          status = Status.SAME;
          ++count;
      }
      cur = A[i];
    }
		Console.WriteLine(count);
	}
}