제출 #489639

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
489639		rainboy	Paprike (COI18_paprike)	C11	100 / 100	57 ms	14744 KiB

paprike

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

#define N	100000

unsigned int X = 12345;

int rand_() {
	return (X *= 3) >> 1;
}

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 aa[N], a_;

void sort(int *ii, int l, int r) {
	while (l < r) {
		int i = l, j = l, k = r, i_ = ii[l + rand_() % (r - l)], tmp;

		while (j < k)
			if (aa[ii[j]] == aa[i_])
				j++;
			else if (aa[ii[j]] < aa[i_]) {
				tmp = ii[i], ii[i] = ii[j], ii[j] = tmp;
				i++, j++;
			} else {
				k--;
				tmp = ii[j], ii[j] = ii[k], ii[k] = tmp;
			}
		sort(ii, l, i);
		l = k;
	}
}

int cnt;

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

	for (o = eo[i]; o--; ) {
		int j = ej[i][o];

		if (j != p)
			dfs(i, j);
	}
	sort(ej[i], 0, eo[i]);
	for (o = 0; o < eo[i]; o++) {
		int j = ej[i][o];

		if (j != p) {
			if (aa[i] + aa[j] <= a_)
				aa[i] += aa[j];
			else
				cnt++;
		}
	}
}

int main() {
	int n, h, i, j;

	scanf("%d%d", &n, &a_);
	for (i = 0; i < n; i++)
		ej[i] = (int *) malloc(2 * sizeof *ej[i]);
	for (i = 0; i < n; i++)
		scanf("%d", &aa[i]);
	for (h = 0; h < n - 1; h++) {
		scanf("%d%d", &i, &j), i--, j--;
		append(i, j), append(j, i);
	}
	dfs(-1, 0);
	printf("%d\n", cnt);
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

paprike.c: In function 'append':
paprike.c:17:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   17 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
paprike.c: In function 'main':
paprike.c:70:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |  scanf("%d%d", &n, &a_);
      |  ^~~~~~~~~~~~~~~~~~~~~~
paprike.c:74:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |   scanf("%d", &aa[i]);
      |   ^~~~~~~~~~~~~~~~~~~
paprike.c:76:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |   scanf("%d%d", &i, &j), i--, j--;
      |   ^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 27 / 27
• Subtask 4: 49 / 49