Submission #1052765

# Submission time Handle Problem Language Result Execution time Memory
1052765 2024-08-10T20:33:12 Z beaconmc COVID tests (CEOI24_covid) C++14
64.88 / 100
1515 ms 704 KB
#include <cassert>
#include <cstdio>
#include <string>
#include <vector>
#include <bits/stdc++.h>
 
typedef long long ll;
#define FOR(i,x,y) for(ll i=x; i<y; i++)
#define FORNEG(i,x,y) for(ll i=x; i>y; i--)
 
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';
}
 
 
vector<ll> dp(ll a, ll b, bool result){
    //cout << a << " " << b << " " << result << endl;
    if (result == 0) return {};
    if (a==b){
        if (result == 1) return {a};
        else return {};
    }
    ll mid = (a+b)/2;
    vector<ll> temp, temp2;
    vector<bool> test(N), test2(N);
    FOR(i,a,mid+1) test[i] = 1;
    FOR(i,mid+1,b+1) test2[i] = 1;
 
    if (rand()%2==0){
        ll result1 = test_students(test);
        temp = dp(a, mid, result1);
        ll result2 = -1;
        if (result1==0) result2 = 1;
        else result2 = test_students(test2);
        temp2 = dp(mid+1, b, result2);
    }else{
        ll result2 = test_students(test2);
        ll result1 = -1;
        temp2 = dp(mid+1, b, result2);
        
        if (result2==0) result1 = 1;
        else result1 = test_students(test);
        temp = dp(a, mid, result1);
        
    }
 
    
    vector<ll> ans;
    for (auto&i : temp) ans.push_back(i);
    for (auto&i : temp2) ans.push_back(i);
    return ans;
}
 
std::vector<bool> find_positive() {
    std::vector<bool> answer(N);
    vector<ll> stuff;
    vector<ll> temp;
    ll c;
    if (P==0.2) c = 4;
    else if (P==0.158765) c = 4;
    else if (P == 0.104571 ) c = 8;
    else if (P == 0.068648 ) c = 8;
    else if (P==0.039856 ) c = 20;
    else if (P == 0.028545 ) c = 32; 
    else if (P==0.011546) c = 64;
    else if (P==0.005256) c = 128;
    else c = 1000;
    //cout << c << endl;
    FOR(i,0,(N-1)/c + 1){
        ll a = c*i;
        ll b = min(c*(i+1)-1, (ll)N-1);
 
        vector<bool> test(N);
        FOR(j,a,b+1) test[j] = 1;
        temp = dp(a, b, test_students(test));
        for (auto&k : temp) stuff.push_back(k);
 
    }
    
    FOR(i,0,N) answer[i] = 0;
    for (auto&i : stuff) answer[i] = 1;
 
    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;
}

Compilation message

Main.cpp: In function 'bool test_students(std::vector<bool>)':
Main.cpp:35:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |     scanf(" %c", &answer);
      |     ~~~~~^~~~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:112:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  112 |     scanf("%d %lf %d", &N, &P, &T);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:128:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  128 |         scanf(" %c", &verdict);
      |         ~~~~~^~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 9 ms 456 KB Output is correct
2 Correct 9 ms 444 KB Output is correct
3 Correct 11 ms 452 KB Output is correct
4 Correct 12 ms 600 KB Output is correct
5 Correct 9 ms 704 KB Output is correct
6 Correct 14 ms 604 KB Output is correct
7 Correct 7 ms 452 KB Output is correct
8 Correct 7 ms 340 KB Output is correct
9 Correct 9 ms 600 KB Output is correct
10 Correct 4 ms 344 KB Output is correct
11 Correct 8 ms 452 KB Output is correct
12 Correct 7 ms 452 KB Output is correct
13 Correct 8 ms 452 KB Output is correct
14 Correct 10 ms 344 KB Output is correct
15 Correct 11 ms 344 KB Output is correct
16 Correct 14 ms 600 KB Output is correct
17 Correct 0 ms 344 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 29 ms 344 KB Output is correct (P=0.001, F=15.1, Q=13.6) -> 90.00 points
2 Correct 112 ms 344 KB Output is correct (P=0.005256, F=51.1, Q=57.9) -> 58.74 points
3 Correct 216 ms 344 KB Output is correct (P=0.011546, F=94.9, Q=109.6) -> 55.57 points
4 Correct 424 ms 340 KB Output is correct (P=0.028545, F=191.5, Q=221.6) -> 55.26 points
5 Correct 533 ms 344 KB Output is correct (P=0.039856, F=246.3, Q=285.7) -> 54.88 points
6 Correct 760 ms 344 KB Output is correct (P=0.068648, F=366.2, Q=407.4) -> 62.07 points
7 Correct 1054 ms 420 KB Output is correct (P=0.104571, F=490.3, Q=533.9) -> 66.39 points
8 Correct 1297 ms 344 KB Output is correct (P=0.158765, F=639.1, Q=670.8) -> 75.10 points
9 Correct 1515 ms 344 KB Output is correct (P=0.2, F=731.4, Q=769.1) -> 74.62 points