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 "pch.h"
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>

#define ll long long
#define fr(i,l,r) for(i=(l);i<(r);i++)
#define min(p,q) ((p)<(q)?(p):(q))
#define max(p,q) ((p)>(q)?(p):(q))
#define INF 1000000000000//10^12



int main(void)
{
	//変数の宣言
	int n;
	int a[100010];

	//よく使う変数
	int i,j,k,l;
	int flag=0;
	int ans=0;
	int count=0;
	int temp,temp1,temp2;
	int max,min;
	int len;
	int sum=0;
	
	
	//データの読み込み
	scanf("%d",&n);
//	scanf_s("%d",&n);

	for(i=0;i<n;i++){
		scanf("%d",&a[i]);
//		scanf_s("%d",&a[i]);
	}

	//	printf("nは%dです\n", n);
	//	printf("データの読み込み終了\n");
	//実際の処理
	
	temp=0;
	ans=1;
	for(i=1;i<n;i++){
		if(temp==0){
			if(a[i]>a[i-1]){
				temp=1;
			}else if(a[i]<a[i-1]){
				temp=-1;
			}
		}else if(a[i]>a[i-1]&&temp==-1){
			ans++;
			temp=0;
		}else if(a[i]<a[i-1]&&temp==1){
			ans++;
			temp=0;
		}
	}

	//	printf("計算部分終了\n");
	
	//出力
	
	printf("%d",ans);

	//	printf("結果の出力終了\n");

	
	return 0;
}