Zigzag

#include <iostream>
using namespace std;

#define MAX 100000

int main() {
	int n;
	cin >> n;
	
	int sequence[MAX];
	for (int i = 0; i < n; i++)
		cin >> sequence[i];
	
	int sequence_we[MAX], mark_we = 0;
	int len = 0;
	for (int i = 0; i < n; i++)
		if (i == n - 1 || sequence[i] != sequence[i+1])
			sequence_we[len++] = sequence[i];
	/*
	for (int i = 0; i < len; i++)
		cout << sequence_we[i] << " ";
	cout << "\n";
	*/
	for (int i = 1; i < len - 1; i++) {
		if (sequence_we[i] < sequence_we[i+1] && sequence_we[i] < sequence_we[i-1])
			mark_we++;
			
		if (sequence_we[i] > sequence_we[i+1] && sequence_we[i] > sequence_we[i-1])
			mark_we++;
	}
	/*
	for (int i = 0; i < len; i++)
		cout << mark_we[i] << " ";
	cout << "\n";
	*/
	
	cout << (mark_we+2);
	return 0;	
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED