Submission #100971

#	Time	Username	Problem	Language	Result	Execution time	Memory
100971		square1001	Question (Grader is different from the original contest) (CEOI14_question_grader)	C++14	100 / 100	1885 ms	78888 KiB

encoder

#include <string>
#include <vector>
#include <algorithm>
#include <functional>
using namespace std;
static bool first_encode = true;
int size_encode = 0;
vector<vector<int> > perm_encode;
int encode(int n, int x, int y) {
	if (first_encode) {
		function<int(int, int)> comb = [&](int n, int m) {
			int ans = 1;
			for (int i = 1; i <= m; ++i) {
				ans = (long long)(ans) * (n - m + i) / i;
			}
			return ans;
		};
		while (comb(size_encode * 2, size_encode) <= n) ++size_encode;
		string perm = string(size_encode, 'o') + string(size_encode, 'x');
		do {
			vector<int> v;
			for (int i = 0; i < size_encode * 2; ++i) {
				if (perm[i] == 'o') v.push_back(i);
			}
			perm_encode.push_back(v);
		} while (next_permutation(perm.begin(), perm.end()));
		first_encode = false;
	}
	vector<int> a = perm_encode[x];
	vector<int> b = perm_encode[y];
	for (int i : a) {
		if (find(b.begin(), b.end(), i) == b.end()) {
			return i + 1;
		}
	}
	return -1;
}

decoder

#include <string>
#include <vector>
#include <algorithm>
#include <functional>
using namespace std;
static bool first_decode = true;
vector<vector<int> > perm_decode;
int size_decode = 0;
int decode(int n, int q, int h) {
	if (first_decode) {
		function<int(int, int)> comb = [&](int n, int m) {
			int ans = 1;
			for (int i = 1; i <= m; ++i) {
				ans = (long long)(ans) * (n - m + i) / i;
			}
			return ans;
		};
		while (comb(size_decode * 2, size_decode) <= n) ++size_decode;
		string perm = string(size_decode, 'o') + string(size_decode, 'x');
		do {
			vector<int> v;
			for (int i = 0; i < size_decode * 2; ++i) {
				if (perm[i] == 'o') v.push_back(i);
			}
			perm_decode.push_back(v);
		} while (next_permutation(perm.begin(), perm.end()));
		first_decode = false;
	}
	vector<int> a = perm_decode[q];
	if (find(a.begin(), a.end(), h - 1) != a.end()) return 1;
	return 0;
}

• Subtask 1: 100 / 100