제출 #1220394

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1220394		KindaGoodGames	COVID tests (CEOI24_covid)	C++20	26.31 / 100	1334 ms	472 KiB

Main

#include<bits/stdc++.h>
#include<chrono>
using namespace std;
/// You may use:
const int BLOCKSZ= 2;

// 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.
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';
}

map<int,int> shuffled;

void rec(int l, int r, vector<bool>& ans){
    if(l == r){
        ans[shuffled[l]] = true;
        return;
    } 
    vector<vector<bool>> blocks(BLOCKSZ, vector<bool>(n));
    
    int bz = ceil((r-l+1)/(double)BLOCKSZ);

    for(int i = l; i <= r; i++){
        int d = i-l;
        blocks[d/bz][shuffled[i]] = true;
    }
    for(int i = 0; i <= min(BLOCKSZ-1,(r-l)); i++){
        auto b = test_students(blocks[i]);
        if(!b) continue;
        rec((bz*i)+l,(bz*(i+1)-1)+l,ans);
    } 
}

/// 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<bool> find_positive() {
    std::vector<bool> answer(n);
    
    rec(0,n-1,answer);

    return answer;
}

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

    // You may perform any extra initialization here.

    vector<int> perm(n);
    iota(perm.begin(),perm.end(), 0);

    unsigned seed = chrono::system_clock::now().time_since_epoch().count();

    // shuffle (perm.begin(), perm.end(), std::default_random_engine(seed));
    for(int i = 0; i < n; i++){ 
        shuffled[perm[i]] = i;
    }

    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:28:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |     scanf(" %c", &answer);
      |     ~~~~~^~~~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:70:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |     scanf("%d %lf %d", &n, &P, &T);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:96:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   96 |         scanf(" %c", &verdict);
      |         ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 0 / 10
• Subtask 2: 26.31 / 90