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>
#define repl(i,l,r)for(long long i=(l);i<(r);i++)
#define rep(i,n) for (long long i = 0; i < (n); ++i)
#define per(i,n) for (long long i = (n); i >= 0; --i)
const int INF = 2147483647;//int max
const long long int MOD = 1000000007;
using namespace std;
using ll = long long;
using P = pair<int,int>;
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }

int main() {
    ll n;
    cin >> n;
    vector<ll> v(n+1,0);
    v[n] = LONG_LONG_MAX;
    rep(i,n)cin >> v[i];
    ll ans = 0;
    repl(i,0,n){
        while(i+1 < n && v[i] == v[i+1])i++;
        if(i+1 < n && v[i] < v[i+1])while(i+1 < n && v[i] <= v[i+1])i++;
        else if(i+1 < n && v[i] > v[i+1])while(i+1 < n && v[i] >= v[i+1])i++;
        ans++;
    }
    cout << ans << endl;
    return 0;
}
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