Submission #491150

#	Time	Username	Problem	Language	Result	Execution time	Memory
491150		rainboy	Pastiri (COI20_pastiri)	C11	8 / 100	291 ms	33332 KiB

pastiri

#include <stdio.h>
#include <stdlib.h>

#define N	500000

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

void append(int **ej, int *eo, 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 main() {
	static int qu[N];
	static char sheep[N];
	int n, k, h, i, j, cnt;

	scanf("%d%d", &n, &k);
	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(ej, eo, i, j), append(ej, eo, j, i);
	}
	for (h = 0; h < k; h++) {
		scanf("%d", &i), i--;
		sheep[i] = 1;
	}
	cnt = 0;
	for (i = -1, j = 0; j < n; j++)
		if (sheep[j]) {
			if (i == -1)
				i = j;
			else if ((i + j) % 2 != 0)
				qu[cnt++] = i, i = j;
			else
				qu[cnt++] = (i + j) / 2, i = -1;
		}
	if (i != -1)
		qu[cnt++] = i, i = -1;
	printf("%d\n", cnt);
	for (h = 0; h < cnt; h++)
		printf("%d ", qu[h] + 1);
	printf("\n");
	return 0;
}

Compilation message (stderr)

pastiri.c: In function 'append':
pastiri.c:11:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   11 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
pastiri.c: In function 'main':
pastiri.c:21:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   21 |  scanf("%d%d", &n, &k);
      |  ^~~~~~~~~~~~~~~~~~~~~
pastiri.c:25:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |   scanf("%d%d", &i, &j), i--, j--;
      |   ^~~~~~~~~~~~~~~~~~~~~
pastiri.c:29:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |   scanf("%d", &i), i--;
      |   ^~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 0 / 18
• Subtask 3: 0 / 23
• Subtask 4: 0 / 51