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: Accepted)

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

int main(){
  int n;
  cin >> n;
  if(n==1){
    cout << 1 << endl;
    return 0;
  }
  vector<int>a(n);
  for(int i=0;i<n;i++)
    cin >> a.at(i);
  int ans=1,x=0;
  while(x+1<n&&a.at(x)==a.at(x+1))
    x++;
  bool zok;
  if(x+1<n)
    zok=a.at(x)<a.at(x+1);
  for(int i=x;i<n-1;i++){
    if(zok){
      if(a.at(i)>a.at(i+1)){
        ans++;
        i++;
        while(i+1<n&&a.at(i)==a.at(i+1))
          i++;
        if(i+1<n)
          zok=a.at(i)<a.at(i+1);
      }
    }else{
      if(a.at(i)<a.at(i+1)){
        ans++;
        i++;
        while(i+1<n&&a.at(i)==a.at(i+1))
          i++;
        if(i+1<n)
          zok=a.at(i)<a.at(i+1);
      }
    }
  }
  cout << ans << endl;
  return 0;
}