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: Wrong Answer)

#include<bits/stdc++.h>
#define rep(i,n,m) for(int i = (n); i <(m); i++)
#define rrep(i,n,m) for(int i = (n) - 1; i >=(m); i--)
using namespace std;
using ll = long long;

int main()
{
    int n;
    cin >> n;
    vector<int> a(n);
    rep(i, 0, n) cin >> a[i];

    int line_type = 0;
    int ans = 0;
    rep(i, 1, n)
    {
        int line_type_now = a[i] - a[i - 1];
        if (line_type != 0)
        {
            if (line_type * line_type_now <= 0)
            {
                ++ans;
                line_type = 0;
            }
        }
        else
            line_type = line_type_now;
        // cout << ans << ' ' << line_type << endl;
    }
    cout << ans + 1 << endl;
    return 0;
}