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>
#define REP(i, n) for (int i = 0; i < (n); i++)
using namespace std;
using ll = long long;

int main() {
    cin.tie(0)->sync_with_stdio(false);

    int n;
    cin >> n;
    vector<int> a(n);
    REP(i, n) cin >> a[i];

    int cnt = 1;
    int sign = 0;
    REP(i, n - 1) {
        int diff = a[i + 1] - a[i];
        if (diff == 0) continue ;
        if (sign) {
            if ((sign == 1 && diff < 0) || (sign == -1 && diff > 0)) {
                sign = 0;
                cnt++;
            }
        } else {
            if (diff > 0) sign = 1;
            else sign = -1;
        }
    }

    cout << cnt << '\n';
    return 0;
}