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 Rust (1.42.0) (judge verdict: Wrong Answer)

#[allow(unused_imports)]
use proconio::marker::{Bytes, Chars, Usize1};
use proconio::{fastout, input};
#[fastout]
fn main() {
    input! {
        n: usize,
        a: [usize; n]
    }
    let mut prev = false;
    let mut next = false;
    let mut count = 1;
    let mut skip = false;
    for i in 0..n - 1 {
        if a[i] == a[i + 1] {
            continue;
        } else if a[i] < a[i + 1] {
            next = true;
        } else {
            next = false;
        }
        if skip {
            skip = false;
            continue;
        }

        if prev == next {
            continue;
        } else {
            count += 1;
            prev = false;
            skip = true;
        }
    }
    println!("{}", count);
}