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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
using namespace std;
 
#define REP(i, s) for (int i = 0; i < s; ++i)
#define ALL(v) (v).begin(), (v).end()
#define COUT(x) cout << #x << " = " << (x) << " (L" << __LINE__ << ")" << endl
#define EACH(i, s) for (__typeof__((s).begin()) i = (s).begin(); i != (s).end(); ++i)
#define DEBUG
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<class T1, class T2> ostream& operator << (ostream &s, pair<T1,T2> P)
{ return s << '<' << P.first << ", " << P.second << '>'; }
template<class T> ostream& operator << (ostream &s, vector<T> P)
{ for (int i = 0; i < P.size(); ++i) { if (i > 0) { s << " "; } s << P[i]; } return s; }
template<class T> ostream& operator << (ostream &s, vector<vector<T> > P)
{ for (int i = 0; i < P.size(); ++i) { s << endl << P[i]; } return s << endl; }
template<class T> ostream& operator << (ostream &s, set<T> P)
{ EACH(it, P) { s << "<" << *it << "> "; } return s << endl; }
template<class T1, class T2> ostream& operator << (ostream &s, map<T1,T2> P)
{ EACH(it, P) { s << "<" << it->first << "->" << it->second << "> "; } return s << endl; }
template<class T>void show(vector<T>v){for (int i = 0; i < v.size(); i++){cerr<<v[i]<<" ";}cerr<<"\n";}
typedef long long ll;
int a[100010];
int main(){
    int n;
    cin>>n;
    REP(i,n) cin>>a[i];
    int cnt=0;
    if(n==1 || n==2) {
        cout<<1<<endl;
        return 0;
    }
    bool flag1=false,flag2=false;
    for (int i = 0; i < n-1; i++)
    {
        if(!flag2&&a[i]<a[i+1]){
            flag1=true;
        }
        if(flag1){
            if(a[i]>a[i+1]){
                cnt++;
                flag1=false;
               // cerr<<i<<endl;
                continue;
            }
        }
          if( !flag1 && a[i]>a[i+1]){
            flag2=true;
        }
        if(flag2){
            if(a[i]<a[i+1]){
                cnt++;
                flag2=false;
              //  cerr<<i<<endl;
                continue;
            }
        }
    }
    cout<<cnt+1<<endl;
    

    return 0;
}