Submission #940805

#	Time	Username	Problem	Language	Result	Execution time	Memory
940805		rainboy	Company Planning (TOKI14_company)	C11	0 / 100	90 ms	10580 KiB

company

#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 dp[N], k;

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 (dp[ii[j]] == dp[i_])
				j++;
			else if (dp[ii[j]] < dp[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;
	}
}

void dfs(int i) {
	int o;

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

		dfs(j);
	}
	sort(ej[i], 0, eo[i]);
	dp[i] = 1;
	for (o = eo[i] - 1; o >= eo[i] - k; o--)
		dp[i] += dp[ej[i][o]];
}

int main() {
	int n, m, i, j, lower, upper;

	scanf("%d%d", &n, &m);
	for (i = 0; i < n; i++)
		ej[i] = (int *) malloc(2 * sizeof *ej[i]);
	for (j = 1; j < n; j++) {
		scanf("%d", &i), i--;
		append(i, j);
	}
	lower = -1, upper = n - 1;
	while (upper - lower > 1) {
		k = (lower + upper) / 2;
		dfs(0);
		if (dp[0] >= m)
			upper = k;
		else
			lower = k;
	}
	printf("%d\n", upper);
	return 0;
}

Compilation message (stderr)

company.c: In function 'append':
company.c:17:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   17 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
company.c: In function 'main':
company.c:60:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |  scanf("%d%d", &n, &m);
      |  ^~~~~~~~~~~~~~~~~~~~~
company.c:64:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |   scanf("%d", &i), i--;
      |   ^~~~~~~~~~~~~~~

• Subtask 1: 0 / 12
• Subtask 2: 0 / 20
• Subtask 3: 0 / 18
• Subtask 4: 0 / 7
• Subtask 5: 0 / 43