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++ (GCC 9.2.1) (judge verdict: Accepted)

#include <bits/stdc++.h>

using ll = long long;
using namespace std;
int main()
{
    int N;
    cin >> N;
    vector<ll> A(N);
    for (ll i = 0; i < N; i++)
    {
        cin >> A[i];
    }
    ll res = 0;
    for (ll i = 0; i < N; i++)
    {
        while (i + 1 < N && A[i + 1] == A[i])
            i++;
        if (A[i + 1] >= A[i])
        {
            while (i + 1 < N && A[i + 1] >= A[i])
            {
                i++;
            }
        }
        else
        {
            while (i + 1 < N && A[i + 1] <= A[i])
            {
                i++;
            }
        }
        res++;
    }
    cout << res << endl;
}