Submission #430450

#	Time	Username	Problem	Language	Result	Execution time	Memory
430450		rainboy	Toy Train (IOI17_train)	C++98	37 / 100	1903 ms	56712 KiB

train

#include "train.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

using namespace std;

const int N = 5000, SMALL = 15, B = 14348907, M = 20000;

typedef vector<int> vi;

int *ej[N], eo[N], *fi[N], fo[N];

void append(int **ej, int *eo, 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 cc[N], qu[N], cnt;

void dfs1(int i) {
	int o;

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

		dfs1(j);
	}
	qu[cnt++] = i;
}

vi rr; char has_[N]; int k, has;

void dfs2(int j, int c) {
	int o;

	if (cc[j] != -1) {
		if (cc[j] != c && has_[cc[j]])
			has_[c] = 1;
		return;
	}
	if (rr[j])
		has = 1;
	cc[j] = c, k++;
	for (o = fo[j]; o--; ) {
		int i = fi[j][o];

		dfs2(i, c);
	}
}

char self[N], right[N];
int adj[SMALL], mask[1 << SMALL], dp[B];

vi who_wins(vi aa, vi rr_, vi uu, vi vv) {
	int n = aa.size(), m = uu.size(), h, i, j, ka, kb;
	vi ans(n);

	rr = rr_;
	ka = kb = 0;
	for (i = 0; i < n; i++)
		if (aa[i] == 1)
			ka++;
		else
			kb++;
	if (n <= SMALL) {
		int x_, p, b;

		x_ = 0;
		for (i = 0; i < n; i++)
			if (!aa[i])
				x_ |= 1 << i;
		for (h = 0; h < m; h++)
			adj[vv[h]] |= 1 << uu[h];
		p = 1;
		for (i = 0; i < n; i++)
			mask[1 << i] = p, p *= 3;
		for (b = 1; b < 1 << n; b++)
			mask[b] = mask[b & b - 1] + mask[b & -b];
		for (b = p - 1; b >= 0; b--) {
			int b_, b1, b2, b1_, b2_;

			b1 = b2 = 0;
			for (i = 0, b_ = b; i < n; i++, b_ /= 3)
				if (b_ % 3 != 0) {
					b1 |= 1 << i;
					if (b_ % 3 == 2)
						b2 |= 1 << i;
				}
			dp[b] = x_;
			for (i = 0; i < n; i++)
				if ((b1 & 1 << i) == 0) {
					b1_ = b1 | 1 << i, b2_ = rr[i] ? b1_ : b2;
					if ((dp[mask[b1_] + mask[b2_]] & 1 << i) != 0)
						dp[b] |= adj[i] & b1 & ~x_;
					else
						dp[b] &= ~(adj[i] & b1 & x_);
				} else if ((b2 & 1 << i) != 0)
					dp[b] |= adj[i] & b1 & ~x_;
				else
					dp[b] &= ~(adj[i] & b1 & x_);
		}
		for (i = 0; i < n; i++)
			ans[i] = (dp[rr[i] ? mask[1 << i] + mask[1 << i] : mask[1 << i]] & 1 << i) != 0;
	} else if (ka == n) {
		for (i = 0; i < n; i++) {
			ej[i] = (int *) malloc(2 * sizeof *ej[i]);
			fi[i] = (int *) malloc(2 * sizeof *fi[i]);
		}
		for (h = 0; h < m; h++) {
			i = vv[h], j = uu[h];
			if (i == j)
				self[i] = 1;
			append(ej, eo, i, j), append(fi, fo, j, i);
		}
		for (i = 0; i < n; i++)
			if (!cc[i])
				dfs1(i);
		while (cnt--) {
			i = qu[cnt];
			if (cc[i] != -1)
				continue;
			k = 0, has = 0, dfs2(i, i);
			if ((k >= 2 || self[i]) && has)
				has_[i] = 1;
		}
		for (i = 0; i < n; i++)
			ans[i] = has_[cc[i]];
	} else if (kb == n) {
		for (i = 0; i < n; i++) {
			ej[i] = (int *) malloc(2 * sizeof *ej[i]);
			fi[i] = (int *) malloc(2 * sizeof *fi[i]);
		}
		for (h = 0; h < m; h++) {
			i = vv[h], j = uu[h];
			if (i == j)
				self[i] = 1;
			if (!rr[i] && !rr[j])
				append(ej, eo, i, j), append(fi, fo, j, i);
		}
		for (i = 0; i < n; i++)
			if (!cc[i])
				dfs1(i);
		while (cnt--) {
			i = qu[cnt];
			if (cc[i] != -1)
				continue;
			k = 0, has = 0, dfs2(i, i);
			if (k >= 2 || !rr[i] && self[i])
				has_[i] = 1;
		}
		for (h = 0; h < m; h++) {
			i = vv[h], j = uu[h];
			if (rr[i] || rr[j])
				append(ej, eo, i, j), append(fi, fo, j, i);
		}
		memset(cc, 0, n * sizeof *cc);
		for (i = 0; i < n; i++)
			if (has_[i])
				dfs1(i);
		for (i = 0; i < n; i++)
			ans[i] = cc[i] == 0;
	} else {
		memset(self, 0, n * sizeof *self), memset(right, 0, n * sizeof *right);
		for (h = 0; h < m; h++)
			if (vv[h] == uu[h])
				self[uu[h]] = 1;
			else
				right[uu[h]] = 1;
		for (i = 0; i < n; i++) {
			ans[i] = 0;
			for (j = i; j < n; j++)
				if (aa[j]) {
					if (rr[j]) {
						if (self[j]) {
							ans[i] = 1;
							break;
						}
					} else {
						if (!right[j]) {
							ans[i] = 0;
							break;
						}
					}
				} else {
					if (rr[j]) {
						if (!right[j]) {
							ans[i] = 1;
							break;
						}
					} else {
						if (self[j]) {
							ans[i] = 0;
							break;
						}
					}
				}
		}
	}
	return ans;
}

Compilation message (stderr)

train.cpp: In function 'void append(int**, int*, int, int)':
train.cpp:17:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   17 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
train.cpp: In function 'vi who_wins(vi, vi, vi, vi)':
train.cpp:85:25: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   85 |    mask[b] = mask[b & b - 1] + mask[b & -b];
      |                       ~~^~~
train.cpp:155:25: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  155 |    if (k >= 2 || !rr[i] && self[i])
      |                  ~~~~~~~^~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 11 / 11
• Subtask 4: 11 / 11
• Subtask 5: 0 / 12
• Subtask 6: 0 / 51