제출 #1137725

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1137725		Faisal_Saqib	COVID tests (CEOI24_covid)	C++20	10 / 100	62 ms	808 KiB

Main

//
// Created by faisal-saqib on 10:23 AM 1/20/25.
//
#include <cassert>
#include <cstdio>
#include <string>
#include <vector>
#include <map>
/// You may use:
using namespace std;
// 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.
vector<vector<bool>> ans_1;
map<vector<bool>,bool> seen;
bool test_students(std::vector<bool> mask) {
    if(seen.find(mask)!=seen.end())
        return seen[mask];
    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);
    // if(answer!='P')
    // {
    //     for(auto&j:ans_1)
    //     {
    //         bool pos=1;
    //         vector<bool> np(N);
    //         for(int i=0;i<N;i++)
    //         {
    //             if(mask[i]==1 && !j[i])
    //             {
    //                 pos=0;
    //                 break;
    //             }
    //             np[i]=(mask[i] xor j[i]);
    //         }
    //         if(pos)
    //             seen[np]=0;
    //     }
    // }
    // else
    // {
    //     ans_1.push_back(mask);
    // }
    return seen[mask]=(answer=='P');
}

/// You should implement:
using namespace std;
int req_len=0;
void recur(int l,int r,vector<bool>&ans,vector<bool>&mk) {
    if (test_students(mk)) {
        if (l==r) {
            return;
        }
        int mid=(l+r)/2;

        for (int p=mid+1;p<=r;p++)mk[p]=0;
        recur(l,mid,ans,mk);

        for (int p=l;p<=mid;p++)mk[p]=0;
        for (int p=mid+1;p<=r;p++)mk[p]=1;
        recur(mid+1,r,ans,mk);
    }
    else {
        for (int i = l; i <= r; i++) {ans[i]=0;}
    }
}

// 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<bool> find_positive() {
    std::vector<bool> answer(N,1),mask(N,1);
    recur(0,N-1,answer,mask);
    return answer;
}

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<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;
}

컴파일 시 표준 에러 (stderr) 메시지

Main.cpp: In function 'bool test_students(std::vector<bool>)':
Main.cpp:34:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |     scanf(" %c", &answer);
      |     ~~~~~^~~~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:95:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   95 |     scanf("%d %lf %d", &N, &P, &T);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:111:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  111 |         scanf(" %c", &verdict);
      |         ~~~~~^~~~~~~~~~~~~~~~~

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