Submission #685247

#	Time	Username	Problem	Language	Result	Execution time	Memory
685247		rainboy	City (JOI17_city)	C++17	100 / 100	407 ms	49552 KiB

Encoder

/* https://www.ioi-jp.org/camp/2017/2017-sp-tasks/2017-sp-d4-city-review.pdf */
#include "Encoder.h"
#include <stdlib.h>

static const int N = 250000, N_ = 601654, H = 18;
static const double B = 1.05;

static int len[N + 1], m;

static void InitEncoder() {
	m = 0;
	len[0] = 1;
	while (len[m] <= N_)
		len[m + 1] = (int) ((len[m] + 1) * B), m++;
}

static int lg(int n) {
	int lower = -1, upper = m;
	while (upper - lower > 1) {
		int h = (lower + upper) / 2;
		if (len[h] >= n)
			upper = h;
		else
			lower = h;
	}
	return upper;
}

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

static 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;
}

static void dfs1(int p, int i, int x) {
	int s = 1;
	for (int o = eo[i]; o--; ) {
		int j = ej[i][o];
		if (j != p) {
			dfs1(i, j, x + s);
			s += len[hh[j]];
		}
	}
	hh[i] = lg(s);
	Code(i, hh[i] * N_ + x);
}

void Encode(int n, int *ii, int *jj) {
	InitEncoder();
	for (int i = 0; i < n; i++)
		ej[i] = (int *) malloc(2 * sizeof *ej[i]);
	for (int h = 0; h < n - 1; h++)
		append(ii[h], jj[h]), append(jj[h], ii[h]);
	dfs1(-1, 0, 0);
}

Device

/* https://www.ioi-jp.org/camp/2017/2017-sp-tasks/2017-sp-d4-city-review.pdf */
#include "Device.h"

static const int N = 250000, N_ = 601654, H = 18;
static const double B = 1.05;

static int len[N + 1];

void InitDevice() {
	int m = 0;
	len[0] = 1;
	while (len[m] <= N_)
		len[m + 1] = (int) ((len[m] + 1) * B), m++;
}

int Answer(long long x, long long y) {
	int ta1 = x % N_, tb1 = ta1 + len[x / N_];
	int ta2 = y % N_, tb2 = ta2 + len[y / N_];
	if (ta2 <= ta1 && tb1 <= tb2)
		return 0;
	if (ta1 <= ta2 && tb2 <= tb1)
		return 1;
	return 2;
}

Compilation message (stderr)

Encoder.cpp: In function 'void append(int, int)':
Encoder.cpp:33:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   33 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~

• Subtask 1: 8 / 8
• Subtask 2: 92 / 92