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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include <vector>

int main()
{
	int n;

	std::cin >> n;

	std::vector<int> a(n);

	for (int i = 0; i < n; i++) {
		std::cin >> a[i];
	}

	int t = 0;
	for (int i = 0; i < n - 1; i++) {
		if (a[i] == a[i + 1]) {
			continue;
		}
		a[t] = a[i];
		t++;
	}
	a[t] = a.back();
	n = t + 1;

	if (n == 1) {
		std::cout << 1 << std::endl;
		return 0;
	}

	bool acsending = true;
	if (a[0] > a[1]) {
		acsending = false;
	}

	int count = 0;

	for (int i = 0; i < n - 1; i++){
		if(acsending){
			if(a[i] > a[i + 1]){
				count++;
				if(i == n - 2){
					break;
				}
				if(a[i + 1] > a[i + 2]){
					acsending = false;
				}
			}
		}else{
			if(a[i] < a[i + 1]){
				count++;
				if(i == n - 2){
					break;
				}
				if(a[i + 1] < a[i + 2]){
					acsending = true;
				}
			}
		}
	}

	std::cout << count + 1 << std::endl;
	return 0;
}