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: Runtime Error)

#include <iostream>
#include <string.h>
#include <string>
#include <algorithm>
#include <math.h>
using namespace std;

void a_sorted_array(void) {
	int n;
	long long int a[10000];
	int ptr_now = 0;
	int ptr_next = ptr_now + 1;
	int state = 0; //1 up, 2 down
	cin >> n;
	for (int i = 0; i < n; i++)cin >> a[i];

	int divide_cnt = 1;
	while (a[ptr_next]!='\0') {
		int sub = a[ptr_next] - a[ptr_now];
		if (sub == 1) {
			if (state == 2) {
				divide_cnt++;
				state = 0;
			}
			else {
				state = 1;
			}
		}
		else if (sub == -1) {
			if (state == 1) {
				divide_cnt++;
				state = 0;
			}
			else {
				state = 2;
			}
		}
		else {
			state = state;
		}
		ptr_now++;
		ptr_next = ptr_now + 1;
	}

	cout << divide_cnt << endl;
}

int main()
{
	a_sorted_array();
    return 0;
}