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: Wrong Answer)

#include <bits/stdc++.h>
 
using namespace std;
 
using ll = long long;
 
int main(){
    ll n; cin >> n;
	ll arr[n];
	for(ll i = 0; i < n; ++i){
		cin >> arr[i];
	}
	ll ans = 0, flag = 0, flag1 = 0;
	for(ll i = 0; i < n;){
		while(arr[i] <= arr[i + 1] && i < n){
			i++;
			flag = 1;
			if(i == n - 1)break;
		}
		if(flag){
			ans++;
			i++;
			flag = 0;
		}
		while(arr[i] >= arr[i + 1] && i < n){
			i++;
			flag1 = 1;
			if(i == n - 1)break;
		}
		if(flag1){
			ans++;
			i++;
			flag1 = 0;
		}
		if(i == n - 1){
			if(n - 3 >= 0 && arr[n - 3] > arr[n - 2] && arr[n - 2] < arr[n - 1])ans++;
			else if(n - 3 >= 0 && arr[n - 3] < arr[n - 2] && arr[n - 2] > arr[n - 1])ans++;
			cout << ans;
			return 0;
		}
	}
	cout << ans;
    return 0;
}