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) for(int i = 0; i < (n); i++)
#define ll long long

using namespace std;

int main(){
  ll n;cin>>n;
  vector<ll> a(n);
  ll result=1;
  if(n<=2){
    cout<<result;
    return 0;
  }
  cin>>a[0];
  cin>>a[1];
  ll pre=a[1]-a[0];
  rep(i, n-2){
    cin>>a[i+2];
    ll t = a[i+2]-a[i+1];
//cout<<t<<' '<<pre<<endl;
    if(t*pre<0){
      result++;
      pre=0;
    }else{
      pre=t;
    }
  }

  cout<<result;

  return 0;
}