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: Accepted)

use std::cmp::Ordering;
use std::io::{stdin, BufRead};
fn main() {
    let stdin = stdin();
    let stdinlock = stdin.lock();
    let mut compare: Option<Ordering> = None;
    let mut current: Option<u32> = None;
    let mut seqs = 1;
    for ak in stdinlock
        .lines()
        .skip(1)
        .next()
        .expect("second line")
        .expect("read")
        .trim()
        .split_whitespace()
        .map(|ak| ak.parse::<u32>().expect("parse error"))
    {
        if let Some(c) = current {
            match ak.cmp(&c) {
                Ordering::Equal => continue,
                current_cmp => {
                    if current_cmp != compare.unwrap_or(current_cmp) {
                        seqs += 1;
                        compare = None;
                    } else {
                        compare = Some(current_cmp);
                    }
                    current = Some(ak);
                    continue;
                }
            }
        } else {
            current = Some(ak);
            continue;
        }
    }
    println!("{}", seqs);
}