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>
#include <stdlib.h>
#define swap(type,a,b) do{type t=a;a=b;b=t;}while(0);
#define MAX(a,b) ((a)>(b)?(a):(b))
#define MIN(a,b) ((a)<(b)?(a):(b))
#define ll long long
#define INF 100000000
#define FOR(i,a,n) for(i=a;i<n;i++)

void fill(int a[],int b,int c){
 	for(int i=0;i<b;i++) a[i]=c;
 	return;
}

int comp(const void *a,const void *b){
    return *(int*)a - *(int*)b;
}
int a[100000];
int main(void)
{
    int n,i,ans=1;
    int size=0;
    scanf("%d",&n);
    FOR(i,0,n){
        scanf("%d",&a[size]);
        if(size>0&&a[size]==a[size-1]) size--;
        size++;
    };
    for(i=0;i<size-2;){
        if(a[i+1]-a[i]>0&&a[i+2]-a[i+1]<0) ans++,i+=2;
        else if(a[i+1]-a[i]<0&&a[i+2]-a[i+1]>0) ans++,i+=2;
        else i++;
    }
    printf("%d\n",ans);
 	return 0;
}