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 Python (3.4.3) (judge verdict: Accepted)

# AGC013A - Sorted Arrays
def main():
    N, *A = map(int, open(0).read().split())
    ans, cur = 0, A[0]
    flg = 0  # unknown (0), increasing (1), decreasing (2)
    for i in A:
        if (flg == 1 and i < cur) or (flg == 2 and i > cur):  # end of trend
            ans += 1
            flg = 0
        elif not flg and cur < i:  # new increasing trend
            flg = 1
        elif not flg and cur > i:  # new decreasing trend
            flg = 2
        cur = i
    print(ans + 1)


if __name__ == "__main__":
    main()