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 <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
const long long INF = 1LL << 60;

void solve(){
    int N;
    scanf("%d", &N);
    vector<long long> A(N);
    for(int i = 0; i < N; i++)scanf("%lld", &A[i]);
    
    int Status = 0;//0...junction, 1...increase, 2...decrease
    int ans = 1;
    
    for(int i = 1; i < N; i++){
        if(Status == 0){
            if(A[i - 1] < A[i])Status = 1;
            if(A[i - 1] > A[i])Status = 2;
        }
        else if(Status == 1 && A[i - 1] > A[i]){
            ans++;
            Status = 0;
        }
        else if(Status == 2 && A[i - 1] < A[i]){
            ans++;
            Status = 0;
        }
    }
    printf("%d\n", ans);
    return;
}
   
int main(void){
    cin.tie(0);
    ios::sync_with_stdio(false);
    std::cout << std::fixed << std::setprecision(15);
    solve();
    return 0;
}