Submission #1177159

#	Time	Username	Problem	Language	Result	Execution time	Memory
1177159		madamadam3	Message (IOI24_message)	C++20	10 / 100	337 ms	872 KiB

message

#include "message.h"
#include <bits/stdc++.h>

using namespace std;

using vb = vector<bool>;
using vvb = vector<vb>;

// strategy 1 (should get 10 points for S <= 64)
// send S packets. if the majority of bits in a packet are 1, then M[i] = 1. else M[i] = 0
// we have 16 (majority) of bits to ourself, so strat always works

// M = message to send, len(M) <= 1024
// C = bitmask of tainted bits, len(C) = 31
// if C[i] = 0, then that bit is safe, otherwise that bit isnt
// 15 unsafe, 16 safe

void send_message(vb M, vb C) {
  vb ZERO = vb(31, false);
  vb ONE = vb(31, true);

  for (int i = 0; i < M.size(); i++) {
    if (M[i] == false) send_packet(ZERO);
    else send_packet(ONE);
  }
}

vb receive_message(vvb R) {
  vb M;

  for (auto &el : R) {
    int ZEROS = 0; for (int i = 0; i < 31; i++) ZEROS += el[i] == false;
    if (ZEROS >= 16) M.push_back(false);
    else M.push_back(true);
  }

  return M;
}

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