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 Go (1.6) (judge verdict: Accepted)

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	sc.Scan()
	iv, _ := strconv.Atoi(sc.Text())
	return iv
}

func init() {
	sc.Split(bufio.ScanWords)
}

func main() {
	n := scanInt()
	a := make([]int, n)
	for i := range a {
		a[i] = scanInt()
	}

	ans := 0
	for i := 0; i < n; i++ {
		ans++
		d := 0
		for j := i + 1; j < n; j++ {
			i = j
			x := a[j] - a[j-1]
			if d == 0 && x != 0 {
				d = x
			}
			if (d > 0 && x < 0) || (d < 0 && x > 0) {
				i = j - 1
				break
			}
		}
	}
	fmt.Println(ans)
}