Submission #488534

#	Time	Username	Problem	Language	Result	Execution time	Memory
488534		rainboy	Logičari (COCI21_logicari)	C11	20 / 110	26 ms	284 KiB

Main

#include <stdio.h>

#define N	20

int min(int a, int b) { return a < b ? a : b; }

int main() {
	static int bb[N];
	int n, h, i, j, b, k_;

	scanf("%d", &n);
	if (n > N) {
		printf("%d\n", n % 4 == 0 ? n / 2 : -1);
		return 0;
	}
	for (h = 0; h < n; h++) {
		scanf("%d%d", &i, &j), i--, j--;
		bb[i] |= 1 << j, bb[j] |= 1 << i;
	}
	k_ = n + 1;
	for (b = 0; b < 1 << n; b++) {
		int b_ = 0, k = 0;

		for (i = 0; i < n; i++)
			if ((b & 1 << i) != 0) {
				if ((b_ & bb[i]) != 0) {
					b_ = -1;
					break;
				}
				b_ |= bb[i], k++;
			}
		if (b_ == (1 << n) - 1)
			k_ = min(k_, k);
	}
	if (k_ == n + 1)
		k_ = -1;
	printf("%d\n", k_);
	return 0;
}

Compilation message (stderr)

Main.c: In function 'main':
Main.c:11:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
Main.c:17:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |   scanf("%d%d", &i, &j), i--, j--;
      |   ^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 40
• Subtask 4: 0 / 50