Submission #1111268

#	Time	Username	Problem	Language	Result	Execution time	Memory
1111268		thieunguyenhuy	Message (IOI24_message)	C++17	100 / 100	2755 ms	1112 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))

#define Int __int128
#define fi first
#define se second

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
typedef pair<long long, int> pli;
typedef pair<int, long long> pil;
typedef vector<pair<int, int>> vii;
typedef vector<pair<long long, long long>> vll;
typedef vector<pair<long long, int>> vli;
typedef vector<pair<int, long long>> vil;

template <class T1, class T2>
bool maximize(T1 &x, T2 y) {
    if (x < y) {
        x = y;
        return true;
    }
    return false;
}
template <class T1, class T2>
bool minimize(T1 &x, T2 y) {
    if (x > y) {
        x = y;
        return true;
    }
    return false;
}

template <class T>
void remove_duplicate(vector<T> &ve) {
    sort (ve.begin(), ve.end());
    ve.resize(unique(ve.begin(), ve.end()) - ve.begin());
}

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
template <class T> T random(T l, T r) {
    return uniform_int_distribution<T>(l, r)(rng);
}
template <class T> T random(T r) {
    return rng() % r;
}

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();
		}
	}

	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] && nxt[u] != -1) {
			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:93:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<bool>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   93 |   if (bitM < M.size()) return bool(M[bitM++]);
      |       ~~~~~^~~~~~~~~~

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