Submission #1222503

#	Time	Username	Problem	Language	Result	Execution time	Memory
1222503		ElenaBM	COVID tests (CEOI24_covid)	C++20	36.95 / 100	1151 ms	408 KiB

Main

#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;
vector<bool> ans;

// 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);

    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 recursion(int l, int r){
    vector<bool>test(N, 0);
    for (int i = l; i <= r; ++i) test[i] = 1;
    if (test_students(test)){ //partir y mirar donde esta
        if (l == r){
            ans[l] = 1;
        }
        else{
            recursion(l, (r+l)/2);
            recursion((r+l)/2 +1, r);
        }
    }
    
}
// 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.
void find_positive() {
    //partir en mitades y revisar cada una --> rollo recursion
    recursion(0, N-1);
}



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

    for (int i = 0; i < T; i++) {
        ans = vector<bool>(N, 0);
        find_positive();
        assert(ans.size() == (size_t)N);

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

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

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

    return 0;
}

Compilation message (stderr)

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:60:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |     scanf("%d %lf %d", &N, &P, &T);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:76:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |         scanf(" %c", &verdict);
      |         ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 10 / 10
• Subtask 2: 26.95 / 90