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 <vector>
#include <algorithm>

using namespace std;
typedef long long ll;

int main(){
    ll n;
    cin >> n;

    int flag=0;    //0:なし, 1:減少, 2:増加
    ll preNum, cnt=1;
    cin >> preNum;

    for(int i=1; i<n; i++){
        ll Num;
        cin >> Num;
        if(Num == preNum) continue;
        if(flag==0){
            if(preNum < Num){
                flag = 2;
            }else{
                flag = 1;
            }
        }else if(flag == 1){
            if(preNum < Num){
                flag = 0;
                cnt++;
            }
        }else{
            if(preNum > Num){
                flag = 0;
                cnt++;
            }
        }
        preNum = Num;
    }

    cout << cnt << endl;
    return 0;
}