oj.uz

Submission #1044101

# Submission time Handle Problem Language Result Execution time Memory
1044101 2024-08-05T07:23:14 Z SamAnd COVID tests (CEOI24_covid) C++17
36.95 / 100
 2239 ms 344 KB 
#include <cassert>
#include <cstdio>
#include <string>
#include <vector>
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.
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';
}

/// You should implement:

void rec(int l, int r, vector<bool>& answer)
{
    vector<bool> v(N, false);
    for (int i = l; i <= r; ++i)
        v[i] = true;
    if (test_students(v) == false)
        return;
    if (l == r)
    {
        answer[l] = true;
        return;
    }
    int m = (l + r) / 2;
    rec(l, m, answer);
    rec(m + 1, r, answer);
}

// 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, false);
    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.

    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;
}

// 1000 0.001 300

Compilation message

Main.cpp: In function 'bool test_students(std::vector<bool>)':
Main.cpp:30:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |     scanf(" %c", &answer);
      |     ~~~~~^~~~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:65:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |     scanf("%d %lf %d", &N, &P, &T);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:81:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |         scanf(" %c", &verdict);
      |         ~~~~~^~~~~~~~~~~~~~~~~

Subtask #0
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 344 KB Output is correct
2 Correct 12 ms 344 KB Output is correct
3 Correct 9 ms 344 KB Output is correct
4 Correct 15 ms 344 KB Output is correct
5 Correct 17 ms 344 KB Output is correct
6 Correct 9 ms 344 KB Output is correct
7 Correct 11 ms 344 KB Output is correct
8 Correct 11 ms 344 KB Output is correct
9 Correct 9 ms 344 KB Output is correct
10 Correct 8 ms 344 KB Output is correct
11 Correct 9 ms 344 KB Output is correct
12 Correct 10 ms 344 KB Output is correct
13 Correct 9 ms 344 KB Output is correct
14 Correct 9 ms 344 KB Output is correct
15 Correct 8 ms 344 KB Output is correct
16 Correct 10 ms 344 KB Output is correct
17 Correct 0 ms 344 KB Output is correct

Subtask #2
26.949999996 / 90.0

# Verdict Execution time Memory Grader output
1 Correct 32 ms 344 KB Output is correct (P=0.001, F=15.1, Q=17.8) -> 52.47 points
2 Correct 158 ms 344 KB Output is correct (P=0.005256, F=51.1, Q=78.0) -> 28.98 points
3 Correct 308 ms 344 KB Output is correct (P=0.011546, F=94.9, Q=150.0) -> 27.09 points
4 Correct 622 ms 344 KB Output is correct (P=0.028545, F=191.5, Q=303.5) -> 26.95 points
5 Correct 769 ms 344 KB Output is correct (P=0.039856, F=246.3, Q=388.5) -> 27.20 points
6 Correct 1132 ms 344 KB Output is correct (P=0.068648, F=366.2, Q=569.4) -> 27.95 points
7 Correct 1468 ms 344 KB Output is correct (P=0.104571, F=490.3, Q=751.4) -> 28.75 points
8 Correct 1852 ms 344 KB Output is correct (P=0.158765, F=639.1, Q=967.6) -> 29.45 points
9 Correct 2239 ms 344 KB Output is correct (P=0.2, F=731.4, Q=1112.6) -> 29.18 points