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: Wrong Answer)

#include <iostream>
using namespace std;

int n, a[100000], b[100000]={0};
int main()
{
    int n;
    scanf("%d",&n);
    for(int i = 0;i < n; i++) 
        cin>>a[i];
    int x=0, y=0;
    for(int i = 1;i < n; i++) {
        b[i+1] = 0x3f3f3f3f;
        if(a[i]<a[i-1]) x = i;
        else b[i+1] = b[x]+1;
        if(a[i]>a[i-1]) y = i;
        else b[i+1] = min(b[i+1],b[y]+1); 
    }
    cout<<b[n]<<endl;  
return 0;
}