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 "bits/stdc++.h"

using namespace std;
using ll = long long;

int direct(int x, int y) {
    if (x == y) return 0;
    if (x > y) return 1;
    return 2;
}

int main() {
    int N;
    cin >> N;

    vector<ll> A(N);
    for (int i = 0; i < N; ++i) cin >> A[i];

    int ans = 1, i = 0;
    while (i < N - 1) {
        if (A[i] == A[i + 1]) {
            ++i;
            continue;
        }
        int group = direct(A[i], A[i + 1]);
        int j = i;
        for (; j < N - 1; ++j) {
            if (A[j] == A[j + 1]) continue;
            if (group != direct(A[j], A[j + 1])) {
                ans += 1;
                break;
            }
        }
        i = j + 1;
    }
    cout << ans << endl;
}