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>
#define rep(i,n) for(int i=0;i<(n);i++)
#define all(v) v.begin(),v.end()
#define len(x) (ll)(x).length()
using namespace std;
typedef long long ll;
typedef pair<int,int> P;
const int INF=1e9;
const ll INFS=1e18;
const int MOD=INF+7;
const int di[] = {-1,0,1,0};
const int dj[] = {0,-1,0,1};

int main(){
  int n;
  cin>>n;
  vector<int> a(n);
  rep(i,n) cin>>a[i];
  int ans=0;
  for(int i=1;i<n;i++){
    if(a[i]>a[i-1]){
      ans++;
      for(;a[i]>=a[i-1];i++){
      }
      i--;
      continue;
    }
    if(a[i]<a[i-1]){
      for(;a[i]<=a[i-1];i++){
      }
    }
    i--;
  }
  cout<<ans+1<<endl;
}