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: Wrong Answer)

#include <stdio.h>
#include <algorithm>
#include <vector>

int main() {
	int n, res = 1;
	bool L[100000], G[100000];
	scanf("%d", &n);
	std::vector<int> A(n);
	for (int i = 0; i < n; i++)
		scanf("%d", &A[i]);
	A.erase(std::unique(A.begin(), A.end()), A.end());
	for (int i = 1; i < A.size(); i++)
		L[i] = A[i] < A[i - 1], G[i] = A[i - 1] < A[i];
	for (int i = 1; i < A.size(); i++)
		if (!((L[i] && L[i - 1]) || (G[i] && G[i - 1])))
			res++, i++;
	printf("%d\n", res);
}