제출 #441873

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
441873		rainboy	Burza (COCI16_burza)	C11	160 / 160	11 ms	868 KiB

burza

/* upsolve after reading analysis */
#include <stdio.h>
#include <stdlib.h>

#define N	400
#define K	19

int max(int a, int b) { return a > b ? a : b; }

int *ej[N], eo[N];

void append(int i, int j) {
	int o = eo[i]++;

	if (o >= 2 && (o & o - 1) == 0)
		ej[i] = (int *) realloc(ej[i], o * 2 * sizeof *ej[i]);
	ej[i][o] = j;
}

int pp[N], tb[N], qu[N], cnt;

void dfs(int p, int i, int d) {
	int o;

	pp[i] = p;
	if (d == 0)
		qu[cnt++] = i;
	for (o = eo[i]; o--; ) {
		int j = ej[i][o];

		if (j != p)
			dfs(i, j, d - 1);
	}
	tb[i] = cnt;
}

int main() {
	static int dp[1 << K];
	int n, k, h, i, j, b, d;

	scanf("%d%d", &n, &k);
	if (k > K) {
		printf("DA\n");
		return 0;
	}
	for (i = 0; i < n; i++)
		ej[i] = (int *) malloc(2 * sizeof *ej[i]);
	for (h = 0; h < n - 1; h++) {
		scanf("%d%d", &i, &j), i--, j--;
		append(i, j), append(j, i);
	}
	dfs(-1, 0, k);
	for (b = 0; b < 1 << k; b++) {
		i = dp[b] == cnt ? -1 : qu[dp[b]];
		for (d = 0; d < k; d++) {
			if ((b & 1 << d) == 0)
				dp[b | 1 << d] = max(dp[b | 1 << d], i == -1 ? cnt : tb[i]);
			if (i != -1)
				i = pp[i];
		}
	}
	printf(dp[(1 << k) - 1] == cnt ? "DA\n" : "NE\n");
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

burza.c: In function 'append':
burza.c:15:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   15 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
burza.c: In function 'main':
burza.c:41:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |  scanf("%d%d", &n, &k);
      |  ^~~~~~~~~~~~~~~~~~~~~
burza.c:49:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |   scanf("%d%d", &i, &j), i--, j--;
      |   ^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 16 / 16
• Subtask 2: 16 / 16
• Subtask 3: 16 / 16
• Subtask 4: 16 / 16
• Subtask 5: 16 / 16
• Subtask 6: 16 / 16
• Subtask 7: 16 / 16
• Subtask 8: 16 / 16
• Subtask 9: 16 / 16
• Subtask 10: 16 / 16