Submission #1111093

#	Time	Username	Problem	Language	Result	Execution time	Memory
1111093		thieunguyenhuy	Message (IOI24_message)	C++17	0 / 100	2531 ms	428 KiB

message

#ifndef hwe
	#include "message.h"
#endif

#include <bits/stdc++.h>
using namespace std;

#define popcount(n) (__builtin_popcountll((n)))
#define clz(n) (__builtin_clzll((n)))
#define ctz(n) (__builtin_ctzll((n)))
#define lg(n) (63 - __builtin_clzll((n)))
#define BIT(n, i) (((n) >> (i)) & 1ll)
#define MASK(i) (1ll << (i))
#define FLIP(n, i) ((n) ^ (1ll << (i)))
#define ON(n, i) ((n) | MASK(i))
#define OFF(n, i) ((n) & ~MASK(i))

const int N = 1e6 + 5;
const int MOD = 1e9 + 7;
const int inf = 1e9;
const long long INF = 1e18;

#ifdef hwe
vector<bool> M, C;
vector<vector<bool>> R;

// vector<bool> send_packet(vector<bool> A) {
// 	assert(A.size() == 31);
// 	for (int i = 0; i < 31; ++i) if (C[i] == 1) {
// 		A[i] = random(2);
// 	}
// 	R.emplace_back(A);
// 	return A;
// }
#endif

void send_message(vector<bool> M, vector<bool> C) {
	vector<int> pos; pos.reserve(16);
	for (int i = 0; i < 31; ++i) if (!C[i]) {
		pos.emplace_back(i);
	}
	assert(pos.size() == 16);
	
	int bitM = 0;
	auto nextBit = [&]() {
		if (bitM < M.size()) return bool(M[bitM++]);
		return !M.back();
	};


	vector<vector<bool>> packets(66, vector<bool>(31, 0));
	// for (int i = 0; i < 16; ++i) {
	// 	int d = (pos[(i + 1) % 16] - pos[i] + 31) % 31;
	// 	packets[d - 1][pos[i]] = 1;
	// 	for (int j = d; j < 66; ++j) {
	// 		packets[j][pos[i]] = nextBit();
	// 	}
	// }

	// cerr << "mkq\n";
	for (auto packet : packets) send_packet(packet);
}

vector<bool> receive_message(vector<vector<bool>> R) {
	vector<int> nxt(31, -1);
	for (int i = 0; i < 66; ++i) {
		vector<bool> packet = R[i];
		for (int j = 0; j < 31; ++j) if (packet[j] && nxt[j] == -1) {
			nxt[j] = (j + i + 1) % 31;
		}
	}

	vector<int> pos; pos.reserve(16);
	for (int i = 0; i < 31; ++i) {
		vector<bool> vis(31, false);
		int u = i, cycleSize = 0;
		while (!vis[u]) {
			vis[u] = true, ++cycleSize;
			u = nxt[u];
		}

		if (cycleSize == 16) {
			for (int j = 0, u = i; j < 16; ++j, u = nxt[u]) {
				pos.emplace_back(u);
			}
			break;
		}
	}

	sort (pos.begin(), pos.end()); vector<bool> M;
	for (int i = 0; i < 16; ++i) {
		int d = (pos[(i + 1) % 16] - pos[i] + 31) % 31;
		for (int j = d; j < 66; ++j) M.emplace_back(R[j][pos[i]]);
	}

	int last = M.back();
	while (M.back() == last) M.pop_back();
	return M;
}

#ifdef hwe
void solve(bool isLocal = false) {
	// M.assign(1024, 0), C.assign(31, 0), R.clear();

    // for (int i = 0; i < M.size(); ++i) {
    // 	M[i] = random(2);
    // }

    // vector<int> index(31); iota(index.begin(), index.end(), 0);
    // shuffle(index.begin(), index.end(), rng);
    // for (int i = 0; i < 15; ++i) C[index[i]] = 1;

    // if (isLocal) {
    // 	cerr << "M = ";
    // 	for (auto x : M) cerr << x;
    // 	cerr << '\n';
    // 	cerr << "C = ";
    // 	for (auto x : C) cerr << x;
    // 	cerr << '\n';
    // }

    // send_message(M, C);
	// vector<bool> ans = receive_message(R);

	// if (isLocal) {
	// 	cerr << "Ans: ";
	// 	for (auto x : ans) cerr << x;
	// 	cerr << '\n';
	// 	if (ans == M) cerr << "Accepted\n";
	// 	else {
	// 		cerr << "Wrong Answer\n";
	// 		exit(0);
	// 	}
	// }
}

signed main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);

    for (int _ = 0; _ < 10; ++_) {
    	solve(true);
    }

    cerr << '\n'; return 0;
}
#endif

Compilation message (stderr)

message.cpp: In lambda function:
message.cpp:46:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<bool>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |   if (bitM < M.size()) return bool(M[bitM++]);
      |       ~~~~~^~~~~~~~~~
message.cpp: In function 'void send_message(std::vector<bool>, std::vector<bool>)':
message.cpp:45:7: warning: variable 'nextBit' set but not used [-Wunused-but-set-variable]
   45 |  auto nextBit = [&]() {
      |       ^~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 0 / 10
• Subtask 2: 0 / 90