Submission #1109503

#	Time	Username	Problem	Language	Result	Execution time	Memory
1109503		8pete8	COVID tests (CEOI24_covid)	C++17	0 / 100	1 ms	336 KiB

Main

#include <cassert>
#include <cstdio>
#include <string>
#include <vector>
using namespace std;
int N;
double P;
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';
}
 
int T;
int answer[1001];
vector<bool>qry;
void solve(int gap){
    int l=0,r=N-1;
    while(l<=N-1){
        r=min(l+gap-1,N-1);
        int pos=N;
        for(int j=0;j<N;j++)qry[j]=0;
        for(int j=l;j<=r;j++)qry[j]=1;
        if(!test_students(qry))return;
        while(l<=r){
            int mid=l+(r-l)/2;
            for(int j=0;j<N;j++)qry[j]=0;
            for(int j=l;j<=mid;j++)qry[j]=1;
            if(test_students(qry))pos=min(pos,mid),r=mid-1;
            else l=mid+1;
        }
        if(pos==N)return;
        l=pos+1;
        answer[pos]=1;
    }
}
void find_positive(int gap){
    solve(gap);
}
int main() {
    scanf("%d %lf %d", &N, &P, &T);
    qry.resize(N);
    for (int i = 0; i < T; i++) {
        for(int j=0;j<N;j++)answer[j]=0;
        int gap;
        if(T==1)gap=1;
        else if(P==0.001)gap=700;
        else if(P==0.005256)gap=138;
        else if(P==0.011546)gap=63;
        else if(P==0.028545)gap=25;
        else if(P==0.039856)gap=17;
        else if(P==0.068648)gap=10;
        else if (P==0.104571)gap=7;
        else if(P==0.158765)gap=5;
        else if(P==0.2)gap=3;
        else assert(0);
        find_positive(gap);
        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 (stderr)

Main.cpp: In function 'bool test_students(std::vector<bool>)':
Main.cpp:18:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |     scanf(" %c", &answer);
      |     ~~~~~^~~~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:49:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |     scanf("%d %lf %d", &N, &P, &T);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:72:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |         scanf(" %c", &verdict);
      |         ~~~~~^~~~~~~~~~~~~~~~~

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