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 whiteread::parse_line;

fn main() {
    let n: usize = parse_line().unwrap();
    let a: Vec<u32> = parse_line().unwrap();
    let mut cnt = 1;

    if n != 1 {
        let mut ord = a[0].cmp(&a[1]);

        for i in 1..n - 1 {
            let nord = a[i].cmp(&a[i + 1]);
            match ord {
                Ordering::Equal => ord = nord,
                Ordering::Less => {
                    if nord == Ordering::Greater {
                        cnt += 1;
                        ord = Ordering::Equal;
                    }
                }
                Ordering::Greater => {
                    if nord == Ordering::Less {
                        cnt += 1;
                        ord = Ordering::Equal;
                    }
                }
            }
        }
    }
    println!("{}", cnt);
}