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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#define MAX 100000
using namespace std;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N;
    int A[MAX];
    cin >> N;
    for (int i = 0; i < N; i++) {
        cin >> A[i];
    }

    int ans = 1;
    int state = 0;
    for (int i = 1; i < N; i++) {
        if (A[i] > A[i-1]) {
            if (state == 0) state = 1;
            else if (state == -1) {
                ans++;
                state = 0;
            }
        }
        else if (A[i] < A[i-1]) {
            if (state == 0) state = -1;
            else if (state == 1) {
                ans++;
                state = 0;
            }
        }
    }

    cout << ans << '\n';
}