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 C (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>

int main(){
    int n, ans = 0;
    int a[100001];
    scanf("%d", &n);
    for(int i = 0; i < n; i++){
        scanf("%d", &a[i]);
    }

    for(int i = 0; i < n; i++){
        while(i < n - 1 && a[i] == a[i + 1]){
            i++;
        }
        if(i < n - 1 && a[i] < a[i + 1]){
            while(i < n - 1 && a[i] <= a[i + 1]){
                i++;
            }
        }
        else if(i < n - 1 && a[i] > a[i + 1]){
            while(i < n - 1 && a[i] >= a[i + 1]){
                i++;
            }
        }
        ans++;
    }
    printf("%d\n", ans);
    return 0;
}