Submission #836269

#	Time	Username	Problem	Language	Result	Execution time	Memory
836269		rainboy	Painting Squares (IOI20_squares)	C++17	100 / 100	184 ms	628 KiB

squares

#include "squares.h"
#include <cstring>
#include <functional>
#include <vector>

using namespace std;

typedef vector<int> vi;

vi paint(int n) {
	const int K = 10, N = 1 << K - 1;
	char used[N * 2]; int qu[N * 2], cnt;
	function<void(int)> dfs = [&](int u) {
		if (!used[u << 1 | 0])
			used[u << 1 | 0] = 1, dfs((u << 1 | 0) & N - 1), qu[cnt++] = u << 1 | 0;
		if (!used[u << 1 | 1])
			used[u << 1 | 1] = 1, dfs((u << 1 | 1) & N - 1), qu[cnt++] = u << 1 | 1;
	};
	memset(used, 0, N * 2 * sizeof *used);
	cnt = 0, dfs(0);
	vi aa(n + 1, 0); aa[n] = K;
	for (int i = K - 1; i < n; i++)
		aa[i] = qu[--cnt] & 1;
	return aa;
}

int find_location(int n, vi cc) {
	const int K = 10, N = 1 << K - 1;
	char used[N * 2]; int qu[N * 2], cnt;
	function<void(int)> dfs = [&](int u) {
		if (!used[u << 1 | 0])
			used[u << 1 | 0] = 1, dfs((u << 1 | 0) & N - 1), qu[cnt++] = u << 1 | 0;
		if (!used[u << 1 | 1])
			used[u << 1 | 1] = 1, dfs((u << 1 | 1) & N - 1), qu[cnt++] = u << 1 | 1;
	};
	memset(used, 0, N * 2 * sizeof *used);
	cnt = 0, dfs(0);
	int u = 0;
	for (int i = 0; i < K; i++) {
		if (cc[i] == -1)
			return n - i;
		u = u << 1 | cc[i];
	}
	for (int h = cnt - 1; h >= 0; h--)
		if (u == qu[h])
			return cnt - 1 - h;
	return -1;
}

Compilation message (stderr)

squares.cpp: In function 'vi paint(int)':
squares.cpp:11:31: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   11 |  const int K = 10, N = 1 << K - 1;
      |                             ~~^~~
squares.cpp: In lambda function:
squares.cpp:15:47: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   15 |    used[u << 1 | 0] = 1, dfs((u << 1 | 0) & N - 1), qu[cnt++] = u << 1 | 0;
      |                                             ~~^~~
squares.cpp:17:47: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   17 |    used[u << 1 | 1] = 1, dfs((u << 1 | 1) & N - 1), qu[cnt++] = u << 1 | 1;
      |                                             ~~^~~
squares.cpp: In function 'int find_location(int, vi)':
squares.cpp:28:31: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   28 |  const int K = 10, N = 1 << K - 1;
      |                             ~~^~~
squares.cpp: In lambda function:
squares.cpp:32:47: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   32 |    used[u << 1 | 0] = 1, dfs((u << 1 | 0) & N - 1), qu[cnt++] = u << 1 | 0;
      |                                             ~~^~~
squares.cpp:34:47: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   34 |    used[u << 1 | 1] = 1, dfs((u << 1 | 1) & N - 1), qu[cnt++] = u << 1 | 1;
      |                                             ~~^~~

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 20 / 20
• Subtask 4: 55 / 55