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
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
#include <iostream>
using namespace std;

int main() {
	int minV = -1000000;
	int maxV = 1000000;
	int n;
	cin >> n;
	int t[n];
	for (int i = 0; i < n; i++) {
		cin >> t[i];
	}
	
	bool inc = true;
	int last = t[0], maxRes = 0;
	bool wrong = false;
	int res = 0;
	for (int i = 1; i < n; i++) {
		if (inc) {
			if (t[i] == last && last == maxV) {
				wrong = true;
				break;
			}
			if (t[i] <= last) {
				++res;
				last = maxV;	
			} else {
				last = t[i];
			}
		} else {
			if (t[i] == last && last == minV) {
				wrong = true;
				break;
			}
			
			if (t[i] >= last) {
				++res;
				last = minV;	
			} else {
				last = t[i];
			}
		}
		
		inc = !inc;
	}
	
	
	///// =======
	
	if (!wrong) {
		maxRes = res;
	}
	
	res = 0;
	inc = false;
	last = t[0];
	wrong = false;
	for (int i = 1; i < n; i++) {
		if (inc) {
			if (t[i] == last && last == maxV) {
				wrong = true;
				break;
			}
			if (t[i] <= last) {
				++res;
				last = maxV;	
			} else {
				last = t[i];
			}
		} else {
			if (t[i] == last && last == minV) {
				wrong = true;
				break;
			}
			
			if (t[i] >= last) {
				++res;
				last = minV;	
			} else {
				last = t[i];
			}
		}
		
		inc = !inc;
	}
	
	if (!wrong && maxRes > res) {
		maxRes = res;
	}
	
	cout << maxRes;
	
	return 0;
}