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 Java7 (OpenJDK 1.7.0) (judge verdict: Wrong Answer)


import java.util.*;
import java.io.*;
public class Main
{
    public static void main(String[] args) throws Exception{
        BufferedReader bff=new BufferedReader(new InputStreamReader(System.in));
        PrintWriter wff=new PrintWriter(System.out);
        bff.readLine();
        String[] st=bff.readLine().split(" ");
        int no=-1;
        int last=-1;
        int res=0;
        for(int i=0;i<st.length;i++){
            int k=Integer.parseInt(st[i]);
            if(last==-1){
                last=k;
            }
            else{
                if(no==-1){
                    if(last-k>0){
                        no=1;
                    }
                    else{
                        no=2;
                    }
                }
                else{
                    if(no==1){
                        if(last-k<=0){
                            no=-1;
                            res++;
                            if(i+1==st.length){
                                res++;
                            }
                        }
                    }
                    else{
                        if(last-k>0){
                            no=-1;
                            res++;
                            if(i+1==st.length){
                                res++;
                            }
                        }
                    }
                }
                last=k;
            }
        }
        if(no!=-1){
            res++;
        }
        wff.println(res);
        wff.flush();
        
    }
}