답안 #1069090

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1069090 2024-08-21T15:46:55 Z huutuan COVID tests (CEOI24_covid) C++14
40.91 / 100
2266 ms 344 KB
#include <cassert>
#include <cstdio>
#include <string>
#include <vector>

#include <bits/stdc++.h>

using namespace std;

/// You may use:

// The number of students
int N;

// The probability any given student is positive
double P;

// This function performs a test on a subset of samples.
// Its argument is a vector of Booleans of length N,
// where the i-th element is true if the i-th sample should be added to the mix.
// It returns true if (and only if) at least one of the samples in the mix is positive.
int test_students(const std::vector<int> &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';
}

/// You should implement:

// This function will be called once for each test instance.
// It should use test_students to determine which samples are positive.
// It must return a vector of Booleans of length N,
// where the i-th element is true if and only if the i-th sample is positive.
std::vector<int> find_positive() {
   vector<int> ans(N);
   vector<int> order(N);
   mt19937 rng(69420);
   // iota(order.begin(), order.end(), 0);
   // shuffle(order.begin(), order.end(), rng);
   auto query=[&](int l, int r) -> int {
      if (l>r) return 0;
      vector<int> test(N);
      for (int i=l; i<=r; ++i) test[i]=1;
      return test_students(test);
   };
   int avg=P*N;
   avg=max(avg, 1);
   int size=N/avg;
   size=max(size, 1);
   if (P==0.2) size=4;
   for (int ll=0, rr=size; ll<N; ll+=size, rr+=size){
      rr=min(rr, N-1);
      if (query(ll, rr)){
         int st=ll;
         do{
            int l=st, r=rr-1;
            while (l<=r){
               int mid=(l+r)>>1;
               if (query(st, mid)) r=mid-1;
               else l=mid+1;
            }
            ans[l]=1;
            st=l+1;
         }while (query(st, rr));
      }
   }
   return ans;
}

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

   // You may perform any extra initialization here.

   for (int i = 0; i < T; i++) {
      std::vector<int> 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

Main.cpp: In function 'int test_students(const std::vector<int>&)':
Main.cpp:33:9: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |    scanf(" %c", &answer);
      |    ~~~~~^~~~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:81:9: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |    scanf("%d %lf %d", &N, &P, &T);
      |    ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:97:12: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   97 |       scanf(" %c", &verdict);
      |       ~~~~~^~~~~~~~~~~~~~~~~
# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 344 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Incorrect 15 ms 344 KB Output isn't correct
2 Halted 0 ms 0 KB -
# 결과 실행 시간 메모리 Grader output
1 Correct 26 ms 344 KB Output is correct (P=0.001, F=15.1, Q=10.7) -> 90.00 points
2 Correct 128 ms 344 KB Output is correct (P=0.005256, F=51.1, Q=47.9) -> 90.00 points
3 Correct 226 ms 344 KB Output is correct (P=0.011546, F=94.9, Q=95.4) -> 88.14 points
4 Correct 477 ms 344 KB Output is correct (P=0.028545, F=191.5, Q=200.3) -> 76.03 points
5 Correct 628 ms 344 KB Output is correct (P=0.039856, F=246.3, Q=264.3) -> 69.64 points
6 Correct 951 ms 344 KB Output is correct (P=0.068648, F=366.2, Q=406.8) -> 62.35 points
7 Correct 1328 ms 344 KB Output is correct (P=0.104571, F=490.3, Q=568.7) -> 54.89 points
8 Correct 1833 ms 344 KB Output is correct (P=0.158765, F=639.1, Q=776.9) -> 48.32 points
9 Correct 2266 ms 344 KB Output is correct (P=0.2, F=731.4, Q=950.8) -> 40.91 points