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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.InputMismatchException;
import java.util.NoSuchElementException;

public class Main{

	static PrintWriter out;
	static InputReader ir;

	static void solve(){
		int n=ir.nextInt();
		int[] a=ir.nextIntArray(n);
		int p=0;
		for(int i=0;i<n-1;i++){
			if(a[i]!=a[i+1])
				a[++p]=a[i+1];
		}
		int cnt=1;
		for(int i=1;i<p-1;i++){
			if((a[i-1]-a[i])*(a[i+1]-a[i])>0){
				cnt++;
				i++;
			}
		}
		out.println(cnt);
	}

	public static void main(String[] args) throws Exception{
		ir=new InputReader(System.in);
		out=new PrintWriter(System.out);
		solve();
		out.flush();
	}

	static class InputReader {

		private InputStream in;
		private byte[] buffer=new byte[1024];
		private int curbuf;
		private int lenbuf;

		public InputReader(InputStream in) {this.in=in; this.curbuf=this.lenbuf=0;}

		public boolean hasNextByte() {
			if(curbuf>=lenbuf){
				curbuf= 0;
				try{
					lenbuf=in.read(buffer);
				}catch(IOException e) {
					throw new InputMismatchException();
				}
				if(lenbuf<=0) return false;
			}
			return true;
		}

		private int readByte(){if(hasNextByte()) return buffer[curbuf++]; else return -1;}

		private boolean isSpaceChar(int c){return !(c>=33&&c<=126);}

		private void skip(){while(hasNextByte()&&isSpaceChar(buffer[curbuf])) curbuf++;}

		public boolean hasNext(){skip(); return hasNextByte();}

		public String next(){
			if(!hasNext()) throw new NoSuchElementException();
			StringBuilder sb=new StringBuilder();
			int b=readByte();
			while(!isSpaceChar(b)){
				sb.appendCodePoint(b);
				b=readByte();
			}
			return sb.toString();
		}

		public int nextInt() {
			if(!hasNext()) throw new NoSuchElementException();
			int c=readByte();
			while (isSpaceChar(c)) c=readByte();
			boolean minus=false;
			if (c=='-') {
				minus=true;
				c=readByte();
			}
			int res=0;
			do{
				if(c<'0'||c>'9') throw new InputMismatchException();
				res=res*10+c-'0';
				c=readByte();
			}while(!isSpaceChar(c));
			return (minus)?-res:res;
		}

		public long nextLong() {
			if(!hasNext()) throw new NoSuchElementException();
			int c=readByte();
			while (isSpaceChar(c)) c=readByte();
			boolean minus=false;
			if (c=='-') {
				minus=true;
				c=readByte();
			}
			long res = 0;
			do{
				if(c<'0'||c>'9') throw new InputMismatchException();
				res=res*10+c-'0';
				c=readByte();
			}while(!isSpaceChar(c));
			return (minus)?-res:res;
		}

		public double nextDouble(){return Double.parseDouble(next());}

		public int[] nextIntArray(int n){
			int[] a=new int[n];
			for(int i=0;i<n;i++) a[i]=nextInt();
			return a;
		}

		public long[] nextLongArray(int n){
			long[] a=new long[n];
			for(int i=0;i<n;i++) a[i]=nextLong();
			return a;
		}

		public char[][] nextCharMap(int n,int m){
			char[][] map=new char[n][m];
			for(int i=0;i<n;i++) map[i]=next().toCharArray();
			return map;
		}
	}
}