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: Accepted)

#include <iostream>
#include <algorithm>

int n;
long long a[100010];
int main(){
  std::cin>>n;
  for(int i=0;i<n;++i)
    std::cin>>a[i];

  long long ans=1;
  int up=0;
  for(int i=0;i<n-1;++i){
    if(up==0){
      if(a[i]<a[i+1])
        up=1;
      else if(a[i]>a[i+1])
        up=-1;
    }
    else if(up>0){
      if(a[i]>a[i+1]){
        ++ans;
        up=0;
      }
    }
    else if(up<0){
      if(a[i]<a[i+1]){
        ++ans;
        up=0;
      }
    }
  }
  
  std::cout<<ans<<std::endl;
  return 0;
}