Zigzag

input/code.cpp: In function 'int main()':
input/code.cpp:9:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
                 ^
input/code.cpp:17:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a);
                  ^

#include <cstdio>
#include <vector>

using namespace std;

int main() {
	int n;

	scanf("%d", &n);

	int a = 0, a_ = 0, a__ = 0;
	int current = 0;
	int longest = 0;
	bool zz_ = false;

	for (int i = 0; i < n; ++i) {
		scanf("%d", &a);
		bool zz = (i >= 2 &&((a < a_ && a_ > a__) || (a > a_ && a_ < a__)));
		a__ = a_;
		a_ = a;
		if (zz) {
			if (!zz_) current = 2;
			++current;
			if (current > longest) longest = current;
		} else {
			current = 0;
		}
		zz_ = zz;
	}
	printf("%d\n", longest);
}

Test 1

Verdict: WRONG ANSWER

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: WRONG ANSWER

Test 15

Verdict: WRONG ANSWER

Test 16

Verdict: WRONG ANSWER

Test 17

Verdict: WRONG ANSWER

Test 18

Verdict: WRONG ANSWER

Test 19

Verdict: WRONG ANSWER

Test 20

Verdict: WRONG ANSWER

Test 21

Verdict: WRONG ANSWER

Test 22

Verdict: WRONG ANSWER

Test 23

Verdict: WRONG ANSWER