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>

using namespace std;

typedef long long ll;

int main(){
 ll N; cin >> N;
  vector<ll> A(N);
  for(ll i = 0; i < N; i++){
    cin >> A[i];}
  
  if( N >= 3){
    ll cnt = 0;
    
    for(ll i = 1; i < N - 1; ){
      if( A[i] > A[i-1] && A[i] > A[i+1]){ cnt++; i += 2;}
      else if( A[i] < A[i-1] && A[i] < A[i+1]){ cnt++; i+= 2;}
      else{ i++;}
       }
    if( cnt == 0){ cout << 0 << endl; return 0;}
    cout << cnt+ 1 << endl; return 0;}
  else{ cout << 1 << endl; return 0;}
}