Submission #1047254

#	Time	Username	Problem	Language	Result	Execution time	Memory
1047254		sleepntsheep	Newspapers (CEOI21_newspapers)	C11	4 / 100	1 ms	604 KiB

newspapers

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


#define N 1005

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

void pus(int i, int j) {
  int o = eo[i]++;
  if (!o) eh[i] = (int*)malloc(2 * sizeof **eh);
  else if (0 == (o & o - 1)) eh[i] = (int*)realloc(eh[i], 2 * o * sizeof **eh);
  eh[i][o] = j;
}

int n, m, col[N];

int dfs(int u, int p) {
  col[u] = 1;
  for (int v, j = 0; j < eo[u]; ++j) if ((v = eh[u][j]) != p) {
    if (col[v])
      return 1;
    if (dfs(v, u))
      return 1;
  }
  return 0;
}


int main() {
  scanf("%d%d", &n, &m);
  for (int u, v, i = 0; i < m; ++i)
    scanf("%d%d", &u, &v), pus(u, v), pus(v, u);

  for (int i = 1; i <= n; ++i)
    if (!col[i] && dfs(i, i)) {
      puts("NO");
      return 0;
    }

  puts("YES");
  puts("1\n1");
}

Compilation message (stderr)

newspapers.c: In function 'pus':
newspapers.c:12:24: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   12 |   else if (0 == (o & o - 1)) eh[i] = (int*)realloc(eh[i], 2 * o * sizeof **eh);
      |                      ~~^~~
newspapers.c: In function 'main':
newspapers.c:31:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |   scanf("%d%d", &n, &m);
      |   ^~~~~~~~~~~~~~~~~~~~~
newspapers.c:33:5: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |     scanf("%d%d", &u, &v), pus(u, v), pus(v, u);
      |     ^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 12
• Subtask 2: 4 / 8
• Subtask 3: 0 / 80