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 namespace std;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define repr(i,n) for(int i = (int)(n); i >= 0; i--)
#define all(v) v.begin(),v.end()
typedef long long ll;

int main(){
    ll N;
    cin >> N;
    vector<ll> A(N);
    rep(i,N){
        cin >> A[i];
    }
    bool plus = true;
    bool minus = true;
    ll ans = 1;
    rep(i,N - 1){
        if (A[i + 1] > A[i]){
            if (!plus){
                plus = true;
                minus = true;
                ans++;
            }
            else{
                minus = false;
            }
        }
        else if (A[i + 1] < A[i]){
            if (!minus){
                plus = true;
                minus = true;
                ans++;
            }
            else{
                plus = false;
            }
        }
    }
    cout << ans << endl;
}