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 5.4.1) (judge verdict: Accepted)

#include <stdio.h>
typedef long long ll;

ll n;
ll a[100005];

int main()
{
	ll ans = 1;
	ll s = 0;

	scanf("%lld", &n);
	for (ll i = 0; i < n; i++) {
		scanf("%lld", &a[i]);
	}

	for (ll i = 1; i < n; i++) {
		if (s != 0) {
			if (s > 0 && a[i] - a[i - 1] < 0) {
				s = 0;
				ans++;
			} else if (s < 0 && a[i] - a[i - 1] > 0) {
				s = 0;
				ans++;
			}
		} else {
			if (a[i] - a[i - 1] > 0) {
				s = 1;
			} else if (a[i] - a[i - 1] < 0) {
				s = -1;
			} else {
				s = 0;
			}
		}
	}

	printf("%lld\n", ans);

	return 0;
}