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>
#include<string.h>
#include<stdlib.h>
#include<math.h>
#define PI 3.141592653589793
#define MOD 1000000007

long int combination(long int n, long int r);

//qsort用、昇順
int compare_int(const void *a, const void *b)
{
	return *(int*)a-*(int*)b;
}
//qsort(data, 10, sizeof(int), compare_int)

long int combination(long int n, long int r)
{
	if(r>n-r) r = n-r;
	if(r == 0) return 1;
	else if(r == 1) return n;
	return (combination(n-1, r) + combination(n-1, r-1));
	//大きくなるとき
	/*
	long int tmp1, tmp2, tmp3;
	tmp1 = combination(n-1, r);
	if(tmp1>=MOD) tmp1 = tmp1%MOD;
	tmp2 = combination(n-1, r-1);
	if(tmp2>=MOD) tmp2 = tmp2%MOD;
	tmp3 = tmp1+tmp2;
	if(tmp3>=MOD) tmp3 = tmp3%MOD;
	return (tmp3);
	*/
}


int main(){
	int n;
	scanf("%d", &n);
	int array[n];
	for(int i=0; i<n; i++){
		scanf("%d", &array[i]);
	}

	int count=1, mode;
	if(array[0]<array[1]) mode=1;
	else mode=-1;
	for(int i=1; i<n-1; i++){
		if(mode==0){
			if(array[i]<array[i+1]) mode=1;
			else mode=-1;
		}
		else if(mode==1){
			if(array[i]>array[i+1]){
				count++;
				mode=0;
			}
		}
		else{
			if(array[i]<array[i+1]){
				count++;
				mode=0;
			}
		}
	}
	printf("%d\n", count);

	return 0;
}