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: Wrong Answer)

#include <stdio.h>
#define MAXN 1<<17
int a[MAXN], n;
int cmp(const int a, const int b) {
    if(a == b) return 0;
    if(a < b) return 1;
    if(a > b) return -1;
}
int solve(void) {
    int res = 1;
    if(n == 1) return 1;
    int mov = cmp(a[0], a[1]);
    for(int i = 2; i < n - 1; i++) {
        int new = cmp(a[i - 1], a[i]);
        if(new == 0) continue;
        if(mov != new) {
            if(mov != 0) {
                res++;
                mov = cmp(a[i], a[i + 1]);
            }
            else mov = new;
        }
    }
    return cmp(a[n - 2], a[n - 1]) != mov && mov != 0 ? res + 1 : res;
} 
int main(void) {
    scanf("%d", &n);
    for(int i = 0; i < n; i++)
        scanf("%d", &a[i]);
    printf("%d", solve());
    return 0;
}