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 9.2.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
using namespace std;
#define int long long

signed main() {
  int N;
  cin >> N;
  vector<int>vec(N);
  for(int i=0; i<N; i++){
    cin >> vec[i];
  }
  int ans = 1;
  for(int i=1; i<N-1; i++){
    if(vec[i-1] == vec[i]){
      continue;
    }
    else if(vec[i-1] <= vec[i] && !(vec[i] <= vec[i+1])){
      ans++;
      i++;
    }
    else if(vec[i-1] >= vec[i] && !(vec[i] >= vec[i+1])){
      ans++;
      i++;
    }
  }
  cout << ans << endl;
}