#include <bits/stdc++.h>
std::vector<bool> send_packet(std::vector<bool> A);
void send_message(std::vector<bool> M, std::vector<bool> C) {
auto hash = [&](const std::string &data) {
uint32_t hash = 2166136261;
for (auto &i : data) {
hash = (hash ^ i) * 16777619;
}
return hash;
};
int bits = 0, i = 0;
while (bits == 0) {
bits += !C[i];
i += !bits;
}
int channel = i;
std::string c_str(31, '0');
for (int i = 0; i < 31; ++i) {
c_str[i] = C[i] + '0';
}
std::string data, ans_str;
int cur = 0;
auto push_bit = [&](bool x) {
ans_str.push_back(x + '0');
while (C[cur % 31]) {
data.push_back('0'), cur++;
}
if (cur / 31 < 31 and cur % 31 == channel) {
data.push_back(c_str[cur / 31]), cur++;
}
while (C[cur % 31]) {
data.push_back('0'), cur++;
}
data.push_back(x + '0'), cur++;
};
auto push_num = [&](int x, int bits) {
for (int i = 0; i < bits; ++i) {
push_bit(x & 1 << i);
}
};
push_num(M.size(), 16);
for (int i = 0; i < M.size(); ++i) {
push_bit(M[i]);
}
push_num(hash(ans_str), 32);
while (cur / 31 < 31) {
push_bit(0);
}
while (cur % 31 != 0) {
data.push_back('0'), cur++;
}
auto send = [&](const std::string &s) {
std::vector<bool> a(s.length());
for (int i = 0; i < s.length(); ++i) {
a[i] = s[i] == '1';
}
send_packet(a);
};
auto send_stream = [&]() {
for (int i = 0; i < data.length(); i += 31) {
send(data.substr(i, 31));
}
};
send_stream();
}
std::vector<bool> receive_message(std::vector<std::vector<bool>> R) {
auto hash = [&](const std::string &data) {
uint32_t hash = 2166136261;
for (auto &i : data) {
hash = (hash ^ i) * 16777619;
}
return hash;
};
for (int channel = 0; channel < 31; ++channel) {
int cur = 0;
std::vector<bool> C(31);
for (int i = 0; i < 31; ++i) {
C[i] = R[cur + i][channel];
}
int j = 0;
int base_cur = cur;
std::string ans_str;
auto recv_bit = [&](bool push) {
while (C[j]) {
cur += (j + 1) / 31, j = (j + 1) % 31;
}
if ((cur - base_cur) < 31 and j == channel) {
cur += (j + 1) / 31, j = (j + 1) % 31;
}
while (C[j]) {
cur += (j + 1) / 31, j = (j + 1) % 31;
}
if (cur > R.size()) {
return 0;
}
int ans = R[cur][j];
cur += (j + 1) / 31, j = (j + 1) % 31;
if (push) {
ans_str.push_back(ans + '0');
}
return ans;
};
auto recv_num = [&](int bits) {
int x = 0;
for (int i = 0; i < bits; ++i) {
x += recv_bit(bits == 16) << i;
}
return x;
};
int size = recv_num(16);
if (size > 1024) {
continue;
}
std::vector<bool> ans(size);
for (int i = 0; i < size; ++i) {
ans[i] = recv_bit(true);
}
if (hash(ans_str) == recv_num(32)) {
return ans;
}
}
return {}; // will never happen
}
