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
52
#include <bits/stdc++.h>

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;

using namespace std;


int main(){
	cin.tie(0);
	ios_base::sync_with_stdio(0);

	int n;
	cin >> n;
	vector<int> t1;
	vector<int> t2;
	for(int i = 0; i < n; i++){
		int x;
		cin >> x;
		t1.push_back(x);
		t2.push_back(x);
	}

	int cnt1 = 0;
	int cnt2 = 0;

	for(int i = 1; i < n; i++){
		if (i%2==0){
			if(t1[i] >= t1[i-1]){
				cnt1++;
				t1[i] = -1000000000;
			}
			if(t2[i] <= t2[i-1]){
				cnt2++;
				t2[i] = 1000000000;
			}
		}
		else{
			if(t1[i] <= t1[i-1]){
				cnt1++;
				t1[i] = 1000000000;
			}
			if(t2[i] >= t2[i-1]){
				cnt2++;
				t2[i] = -1000000000;
			}
		}
	}

	cout << min(cnt1, cnt2) << "\n";
}