Submission #1114864

#	Time	Username	Problem	Language	Result	Execution time	Memory
1114864		PagodePaiva	COVID tests (CEOI24_covid)	C++17	10 / 100	5338 ms	504 KiB

Main

#include <cassert>
#include <cstdio>
#include <string>
#include <vector>
#include<bits/stdc++.h>

using namespace std;

int N;
double P;
int tam;

bool test_students(std::vector<bool> mask) {
    assert(mask.size() == (size_t)N);

    std::string mask_str(N, ' ');
    for (int i = 0; i < N; i++)
        mask_str[i] = mask[i] ? '1' : '0';

    printf("Q %s\n", mask_str.c_str());
    fflush(stdout);

    char answer;
    scanf(" %c", &answer);
    return answer == 'P';
}

set <int> find(vector <bool> &v){
  int con = 0;
  for(int i = 0;i < v.size();i++){
    if(v[i]) con++;
  }
  if(con == 1){
    set <int> res;
    for(int i = 0;i < v.size();i++){
      if(v[i]) res.insert(i);
    }
    return res;
  }
  vector <bool> a1(N), a2(N);
  int d = 0;
  for(int i = 0;i < v.size();i++){
    int p = con/2;
    a1[i] = false;
    a2[i] = false;
    if(v[i]){
      if(d < p){
        a1[i] = true;
      }
      else{
        a2[i] = true;
      }
      d++;
    }
  }
  set <int> ans;
  if(test_students(a1)){
    set <int> aux = find(a1);
    for(auto x : aux){
      ans.insert(x);
    }
  }
  if(test_students(a2)){
    set <int> aux2 = find(a2);
    for(auto x : aux2){
      ans.insert(x);
    }
  }
  return ans;
}

std::vector<bool> find_positive() {
    std::vector<bool> answer(N);
    int n = N;
    vector <bool> v;    
    int tam = 1;
    vector <int> idx;
    for(int i = 0;i < n;i++){
      idx.push_back(i);
      answer[i] = false;
    }
    random_shuffle(idx.begin(), idx.end());
    for(int i = 0;i < n;i += tam){
      v.clear();
      for(int j = 0;j < n;j++){
        v.push_back(false);
      }
      for(int j = i;j < min(i+tam, n);j++){
        v[idx[j]] = true;
      }
      if(!test_students(v)) continue;
      set <int> aux = find(v);
      for(auto x : aux){
        answer[x] = true;
      }
    }
    return answer;
}

int main() {
    srand(69);
    int T;
    scanf("%d %lf %d", &N, &P, &T);

    // You may perform any extra initialization here.
    P = 1-P;
    int p = P;
    tam = 1;
    while(P > 0.5){
      P *= p;
      tam++;
      if(tam == N) break;
    }
    for (int i = 0; i < T; i++) {
        std::vector<bool> answer = find_positive();
        assert(answer.size() == (size_t)N);

        std::string answer_str(N, ' ');
        for (int j = 0; j < N; j++)
            answer_str[j] = answer[j] ? '1' : '0';

        printf("A %s\n", answer_str.c_str());
        fflush(stdout);

        char verdict;
        scanf(" %c", &verdict);
        if (verdict == 'W')
            exit(0);
    }

    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'std::set<int> find(std::vector<bool>&)':
Main.cpp:30:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<bool>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |   for(int i = 0;i < v.size();i++){
      |                 ~~^~~~~~~~~~
Main.cpp:35:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<bool>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |     for(int i = 0;i < v.size();i++){
      |                   ~~^~~~~~~~~~
Main.cpp:42:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<bool>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |   for(int i = 0;i < v.size();i++){
      |                 ~~^~~~~~~~~~
Main.cpp: In function 'bool test_students(std::vector<bool>)':
Main.cpp:24:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |     scanf(" %c", &answer);
      |     ~~~~~^~~~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:103:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  103 |     scanf("%d %lf %d", &N, &P, &T);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:126:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  126 |         scanf(" %c", &verdict);
      |         ~~~~~^~~~~~~~~~~~~~~~~

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