제출 #480031

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
480031		rainboy	Lutrija (COCI19_lutrija)	C11	70 / 70	579 ms	324 KiB

lutrija

#include <stdio.h>

int prime(long long p) {
	long long a;

	if (p <= 1)
		return 0;
	for (a = 2; a <= p / a; a++)
		if (p % a == 0)
			return 0;
	return 1;
}

int main() {
	long long a, b;

	scanf("%lld%lld", &a, &b);
	if (a != 2 && !prime(a - 2) && !prime(a + 2) || b != 2 && !prime(b - 2) && !prime(b + 2))
		printf("-1\n");
	else {
		int cnt = 1;

		if (prime(a - 2))
			cnt++;
		else if (prime(a + 2))
			cnt += 2;
		if (prime(b - 2))
			cnt++;
		else if (prime(b + 2))
			cnt += 2;
		printf("%d\n", cnt);
		if (prime(a - 2))
			printf("%lld ", a);
		else if (prime(a + 2))
			printf("%lld %lld ", a, a + 2);
		printf("2");
		if (prime(b - 2))
			printf(" %lld", b);
		else if (prime(b + 2))
			printf(" %lld %lld", b + 2, b);
		printf("\n");
	}
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

lutrija.c: In function 'main':
lutrija.c:18:30: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   18 |  if (a != 2 && !prime(a - 2) && !prime(a + 2) || b != 2 && !prime(b - 2) && !prime(b + 2))
      |      ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
lutrija.c:17:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |  scanf("%lld%lld", &a, &b);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 7 / 7
• Subtask 4: 7 / 7
• Subtask 5: 7 / 7
• Subtask 6: 7 / 7
• Subtask 7: 7 / 7
• Subtask 8: 7 / 7
• Subtask 9: 7 / 7
• Subtask 10: 7 / 7