1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
#include <iostream>

using namespace std;

int check(bool isFirstHigh, int*& sounds, int len) {
	int out = 0;
	bool isHigh = isFirstHigh;
	int last = ((isFirstHigh) ? -1e7 : 1e7);
	for (int i = 0; i < len; i++) {
		if (isHigh) {
			if (sounds[i] <= last) {
				out++;
				last = 1e7;
			}else
				last = sounds[i];
		}
		else {
			if (sounds[i] >= last) {
				out++;
				last = -1e7;
			}
			else
				last = sounds[i];
		}


		isHigh = !isHigh;
	}

	return out;
}

int main() {
	int n;
	cin >> n;
	int* sounds = new int[n];

	for (int i = 0; i < n; i++) {
		cin >> sounds[i];
	}

	int tmp1 = check(1, sounds, n);
	int tmp2 = check(0, sounds, n);

	if (tmp2 < tmp1) tmp1 = tmp2;

	cout << tmp1;


	return 0;
}