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 (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>

int A[100005];
int dot[100005];

int main() {

	int N;

	scanf("%d",&N);

	int i;

	for (i = 0; i < N; i++) {
		scanf(" %d",&A[i]);
	}

	i = 0;

	while (1) {
		if (i >= N - 1) { break; }

		int cnt = 0;
		int start;
		while (1) {
			if (i >= N - 1) { break; }
			if (cnt == 0) {
				if (A[i] < A[i + 1]) {
					start = 0;
				}
				else if (A[i] > A[i + 1]) {
					start = 1;
				}
				else {
					while (1) {
						if (i >= N - 1 || A[i] != A[i + 1]) { break; }
						i++;
					}

					if(i<N-1){
						if (A[i] < A[i + 1]) {
							start = 0;
						}
						else if (A[i] > A[i + 1]) {
							start = 1;
						}
					}

				}
			}
			else {
				if (start == 0 && A[i] > A[i+1]) {
					dot[i] = 1;
					i++;
					break;
				}
				if (start == 1 && A[i] < A[i + 1]) {
					dot[i] = 1;
					i++;
					break;
				}
			}
			cnt++;
			i++;
		}


	}

	int ans = 1;
	for (i = 0; i < N - 1; i++) {
		if (dot[i] == 1) { ans++; }
	}

	printf("%d\n",ans);

	return 0;
}