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>
using Int = long long;

int main() {

	Int N;
	std::cin >> N;

	std::vector<int> A(N);
	for (Int i = 0; i < N; i++)std::cin >> A[i];

	Int ans = 0;
	int flag = 0;//0未定、1単調非増加中、2単調非減少中
	for (Int i = 0; i < N - 1; i++) {
		if (flag == 0) {
			if (A[i + 1] - A[i] > 0)flag = 2;
			else if (A[i + 1] - A[i] < 0)flag = 1;
		}
		else if (flag == 1) {
			if (A[i + 1] - A[i] > 0) {
				flag = 0;
				ans++;
			}

		}
		else if (flag == 2) {
			if (A[i + 1] - A[i] < 0) {
				flag = 0;
				ans++;
			}
		}

	}

	std::cout << ans+1 << std::endl;
}