Submission #478884

#	Time	Username	Problem	Language	Result	Execution time	Memory
478884		rainboy	Wand (COCI19_wand)	C11	70 / 70	38 ms	4760 KiB

wand

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

#define N	100000

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;
}

char visited[N + 1];

void dfs(int i) {
	int o;

	if (visited[i])
		return;
	visited[i] = 1;
	for (o = eo[i]; o--; ) {
		int j = ej[i][o];

		dfs(j);
	}
}

int main() {
	int n, m, i, j, o;

	scanf("%d%d", &n, &m);
	for (i = 0; i < n; i++)
		ej[i] = (int *) malloc(2 * sizeof *ej[i]);
	while (m--) {
		scanf("%d%d", &j, &i), i--, j--;
		append(i, j);
	}
	if (eo[0] == 0)
		visited[0] = 1;
	else
		for (o = eo[0]; o--; ) {
			j = ej[0][o];
			dfs(j);
		}
	for (i = 0; i < n; i++)
		visited[i] += '0';
	printf("%s\n", visited);
	return 0;
}

Compilation message (stderr)

wand.c: In function 'append':
wand.c:11:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   11 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
wand.c: In function 'main':
wand.c:34:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |  scanf("%d%d", &n, &m);
      |  ^~~~~~~~~~~~~~~~~~~~~
wand.c:38:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |   scanf("%d%d", &j, &i), i--, j--;
      |   ^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 70 / 70