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>

int main(int argc, char **argv)
{
    int N;
    std::cin >> N;

    std::vector<int> A(N);
    for(int i = 0; i < N; i++){
        std::cin >> A.at(i);
    }

    int num = 1;
    int a = A.at(0);
    int diff = 0;
    for(int i = 1; i < N; i++){
        int nd = A.at(i) - a;
        a = A.at(i);
        if(nd == 0 || diff == 0 || (nd < 0 && diff < 0) || (nd > 0 && diff > 0)){
            if(nd != 0){
                diff = nd;
            }
        }else{
            num++; // new seriese
            diff = 0;
        }
    }
    std::cout << num << std::endl;
    
}