Submission #873210

#	Time	Username	Problem	Language	Result	Execution time	Memory
873210		rainboy	Shuffle (NOI19_shuffle)	C++17	48 / 100	2 ms	2652 KiB

shuffle

#include "shuffle.h"
#include <cstring>
#include <vector>

using namespace std;

const int N = 1000, L = 10;	/* L = ceil(log2(N)) */

typedef vector<int> vi;
typedef vector<vi> vvi;

int pp[L], xx[N], idx[N * N], xx_[N];
int uu[N], vv[N];

vi solve(int n, int m, int k, int q, int s) {
	vvi iii(m), aaa;
	vi aa(n);
	if (s == 3) {
		int l = 0, p = 1;
		while (p < n)
			pp[l++] = p, p *= m;
		for (int i = 0; i < n; i++) {
			int d = i % m, x = d;
			for (int h = 1; h < l; h++) {
				int d_ = (i / pp[h] + d) % m;
				x += d_ * pp[h];
			}
			idx[xx[i] = x] = i;
		}
		memset(xx_, 0, n * sizeof *xx_);
		for (int h = 0; h < l; h++) {
			for (int d = 0; d < m; d++)
				iii[d].clear();
			for (int i = 0; i < n; i++)
				iii[xx[i] / pp[h] % m].push_back(i + 1);
			aaa = shuffle(iii);
			for (int d = 0; d < m; d++)
				for (int g = 0; g < k; g++)
					xx_[aaa[d][g] - 1] += d * pp[h];
		}
		for (int a = 0; a < n; a++)
			aa[idx[xx_[a]]] = a + 1;
	} else if (s == 2 || s == 4) {
		for (int d = 0; d < n / 2; d++)
			iii[d].clear();
		for (int d = 0; d < n / 2; d++)
			iii[d] = { d * 2 + 1, d * 2 + 2 };
		aaa = shuffle(iii);
		for (int d = 0; d < n / 2; d++) {
			int a = aaa[d][0] - 1, b = aaa[d][1] - 1;
			uu[a] = b, uu[b] = a;
		}
		for (int d = 0; d + 1 < n / 2; d++)
			iii[d] = { d * 2 + 2, d * 2 + 3 };
		iii[n / 2 - 1] = { n, 1 };
		aaa = shuffle(iii);
		for (int d = 0; d < n / 2; d++) {
			int a = aaa[d][0] - 1, b = aaa[d][1] - 1;
			vv[a] = b, vv[b] = a;
		}
		for (int i = 2, j = n - 1; j - i > 3; i++, j--)
			iii[i - 2] = { i + 1, j + 1 };
		iii[n / 2 - 3] = { n / 2, n / 2 + 2 }, iii[n / 2 - 2] = { n / 2 + 1, n / 2 + 3 };
		iii[n / 2 - 1] = { 1, 2 };
		aaa = shuffle(iii);
		int a_ = -1, b_ = -1;
		for (int d = 0; d < n / 2; d++) {
			int a = aaa[d][0] - 1, b = aaa[d][1] - 1;
			if (uu[a] == b) {
				a_ = a, b_ = b;
				break;
			}
		}
		for (int i = 1, j = n - 2; j - i > 3; i++, j--)
			iii[i - 1] = { i + 1, j + 1 };
		iii[n / 2 - 3] = { n / 2 - 1, n / 2 + 1 }, iii[n / 2 - 2] = { n / 2, n / 2 + 2 };
		iii[n / 2 - 1] = { n, 1 };
		aaa = shuffle(iii);
		for (int d = 0; d < n / 2; d++) {
			int a = aaa[d][0] - 1, b = aaa[d][1] - 1;
			if (vv[a] == b) {
				if (b_ == a || b_ == b)
					a_ = b_;
				break;
			}
		}
		for (int i = 0, a = a_; i < n; i++) {
			aa[i] = a + 1;
			a = i % 2 == 0 ? uu[a] : vv[a];
		}
	} else if (s == 1 || s == 5) {
		int l = 0;
		while (1 << l < n)
			l++;
		l++;
		for (int i = 0; i < n; i++) {
			int x = (i < n - 2 ? i : 1 << l - 1 ^ i & 1) ^ ((i & 1) == 0 ? 0 : (1 << l) - 2);
			idx[xx[i] = x] = i;
		}
		memset(xx_, 0, n * sizeof *xx_);
		for (int h = 0; h < l; h++) {
			for (int d = 0; d < 2; d++)
				iii[d].clear();
			for (int i = 0; i < n; i++)
				iii[xx[i] >> h & 1].push_back(i + 1);
			aaa = shuffle(iii);
			for (int g = 0; g < n / 2; g++)
				xx_[aaa[1][g] - 1] ^= 1 << h;
		}
		for (int h = 1; h < l; h++) {
			int d = 0;
			for (int a = 0; a < n; a++)
				d += (xx_[a] >> h & 1) == (xx_[a] & 1) ? 1 : -1;
			if (d < 0)
				for (int a = 0; a < n; a++)
					xx_[a] ^= 1 << h;
		}
		for (int d = 0; d < 2; d++)
			iii[d].clear();
		iii[0].push_back(1);
		for (int i = 2; i <= n / 2; i++)
			iii[0].push_back(i + 1);
		iii[1].push_back(2);
		for (int i = n / 2 + 1; i < n; i++)
			iii[1].push_back(i + 1);
		aaa = shuffle(iii);
		for (int d = 0; d < 2; d++)
			for (int g = 0; g < n / 2; g++)
				if (xx_[aaa[d][g] - 1] == 0) {
					int flip = 1;
					for (g = 0; g < n / 2; g++)
						if (xx_[aaa[d][g] - 1] == 2) {
							flip = 0;
							break;
						}
					if (flip)
						for (int a = 0; a < n; a++)
							xx_[a] ^= (1 << l) - 1;
					goto out;
				}
out:
		for (int a = 0; a < n; a++)
			aa[idx[xx_[a]]] = a + 1;
	}
	return aa;
}

Compilation message (stderr)

shuffle.cpp: In function 'vi solve(int, int, int, int, int)':
shuffle.cpp:97:36: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   97 |    int x = (i < n - 2 ? i : 1 << l - 1 ^ i & 1) ^ ((i & 1) == 0 ? 0 : (1 << l) - 2);
      |                                  ~~^~~
shuffle.cpp:97:44: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   97 |    int x = (i < n - 2 ? i : 1 << l - 1 ^ i & 1) ^ ((i & 1) == 0 ? 0 : (1 << l) - 2);
      |                                          ~~^~~

• Subtask 1: 2 / 2
• Subtask 2: 3 / 3
• Subtask 3: 12 / 12
• Subtask 4: 16 / 16
• Subtask 5: 15 / 15
• Subtask 6: 0 / 52