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)

#![allow(unused_imports)]

use std::{i32, i64, u32, u64, usize, f64};
use std::cmp::{max, min, Ordering};
use std::collections::*;
use std::io::{stdout, Write, BufWriter};
use std::mem::{swap};
use maplit::*;
use proconio::marker::{Isize1, Usize1, Bytes, Chars};

#[proconio::fastout]
fn main() {
    proconio::input!{
        n: usize,
        mut arr: [i32; n],
    }
    arr.dedup();
    let n = arr.len();
    if n == 1 {
        println!("1");
        return;
    }
    let mut skip = false;
    let mut state = arr[0].cmp(&arr[1]);
    let mut ans = 1;
    for i in 0..n - 1 {
        let rel = arr[i].cmp(&arr[i + 1]);
        if skip {
            state = rel;
            skip = false;
        }
        else if state != rel {
            ans += 1;
            skip = true;
        }
    }
    println!("{}", ans);
}