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 Kotlin (1.3.71) (judge verdict: Accepted)

fun main(arr: Array<String>) {
    val n = readLine()!!.toInt()
    val r = readLine()!!.split(" ").map { it.toLong() }
    val fixed = mutableListOf(r.first())
    for(i in (1 until n)) {
        if(r[i] != fixed.last()) {
            fixed.add(r[i])
        }
    }
    var isBigger = true
    if(fixed.size >= 2) {
        isBigger = fixed[0] < fixed[1]
    }
    var ans = 1
    var idx = 1
    if(fixed.size >= 2) {
        while (idx < fixed.size) {
            if(isBigger) {
                if(fixed[idx-1] < fixed[idx]) {
                    idx++
                    continue
                }
            } else {
                if(fixed[idx-1] > fixed[idx]) {
                    idx++
                    continue
                }
            }
            if(idx < fixed.size - 1) {
                isBigger = fixed[idx] <= fixed[idx+1]
            }
            ans++
            idx+=1
        }
    }
    println(ans)
}