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>
#include<vector>
using namespace std;
int main(){
    int N;
    cin>>N;
    vector<int> A(N);
    for(int i=0;i<N;i++)    cin>>A[i];
    int tmp=A[0];
    int res=1,flag=-1;
    for(int j=0;j<N;j++){
        if(tmp>A[j]) {
            if(flag==1){
                res++;
                flag=-1;
            }else{
                flag=0;
            }
        }
        if (tmp < A[j])
        {
            if (flag == 0)
            {
                res++;
                flag = -1;
            }
            else{
                flag = 1;
            }
        }
        

        //if(tmp<A[j])    flag=1;//increse
        //if(tmp>A[j])    flag=0;//decrease
        tmp=A[j];
        //cout<<flag<<endl;
    }
    
    cout<<res<<endl;
    return 0;
}