oj.uz

Submission #1052719

# Submission time Handle Problem Language Result Execution time Memory
1052719 2024-08-10T19:52:34 Z beaconmc COVID tests (CEOI24_covid) C++14
53.96 / 100
 1519 ms 600 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>=0.068648) c = 4;
    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:105:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  105 |     scanf("%d %lf %d", &N, &P, &T);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:121:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  121 |         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 8 ms 448 KB Output is correct
2 Correct 10 ms 444 KB Output is correct
3 Correct 8 ms 340 KB Output is correct
4 Correct 11 ms 448 KB Output is correct
5 Correct 8 ms 440 KB Output is correct
6 Correct 8 ms 344 KB Output is correct
7 Correct 7 ms 448 KB Output is correct
8 Correct 6 ms 444 KB Output is correct
9 Correct 6 ms 344 KB Output is correct
10 Correct 3 ms 344 KB Output is correct
11 Correct 6 ms 444 KB Output is correct
12 Correct 6 ms 344 KB Output is correct
13 Correct 11 ms 344 KB Output is correct
14 Correct 5 ms 444 KB Output is correct
15 Correct 6 ms 344 KB Output is correct
16 Correct 8 ms 444 KB Output is correct
17 Correct 1 ms 344 KB Output is correct

Subtask #2
43.959999996 / 90.0

# Verdict Execution time Memory Grader output
1 Correct 25 ms 344 KB Output is correct (P=0.001, F=15.1, Q=13.6) -> 90.00 points
2 Correct 122 ms 344 KB Output is correct (P=0.005256, F=51.1, Q=60.9) -> 50.93 points
3 Correct 218 ms 412 KB Output is correct (P=0.011546, F=94.9, Q=117.7) -> 45.89 points
4 Correct 480 ms 600 KB Output is correct (P=0.028545, F=191.5, Q=241.4) -> 44.07 points
5 Correct 616 ms 344 KB Output is correct (P=0.039856, F=246.3, Q=310.8) -> 43.96 points
6 Correct 831 ms 344 KB Output is correct (P=0.068648, F=366.2, Q=446.6) -> 47.92 points
7 Correct 1041 ms 420 KB Output is correct (P=0.104571, F=490.3, Q=540.8) -> 63.74 points
8 Correct 1372 ms 344 KB Output is correct (P=0.158765, F=639.1, Q=670.8) -> 75.10 points
9 Correct 1519 ms 344 KB Output is correct (P=0.2, F=731.4, Q=769.1) -> 74.62 points