| # | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1076882 | 2024-08-26T17:46:07 Z | abouton | COVID tests (CEOI24_covid) | C++17 | 2598 ms | 344 KB |
#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;
int K = 3;
vector<bool> answer;
// 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';
}
void tester(int a, int b)
{
//printf("%d %d\n", a, b);
if (b <= a) return;
if (b==a+1)
{
vector<bool> quest(N);
quest[a] = true;
answer[a] = test_students(quest);
return;
}
vector<bool> quest(N);
for (int i = a; i < b; i ++) quest[i] = true;
if (!test_students(quest)) return;
int t = (b-a)/K;
int r = (b-a)%K;
int nbit = 0, cur = a;
while (cur < b)
{
int deb = cur;
cur += t;
cur += (nbit<r);
nbit++;
//printf("%d a %d\n", deb, cur);
tester(deb, cur);
}
}
/// You should implement:
// 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.
vector<bool> find_positive() {
if (P<0.01 || P > 0.012)
{
answer.clear();
answer.resize(N);
tester(0,N);
}
else
{
int restants = N;
answer.clear();
answer.resize(N);
for (int i = 0; i < N; i ++) answer[i] = true;
int taille;
for (int x = 0; x < 50; x ++)
{
vector<bool> quest(N);
//printf("\n%d\n", restants);
for (int i =0; i < N; i ++)
{
if (!answer[i]) continue;
int rep = (rand()%(restants/35) == 0);
if (rep) quest[i] = true;
}
if (!test_students(quest)) {for (int i = 0; i < N; i ++) {if (quest[i]) {answer[i] = 0; restants -= 1;}}}
}
vector<bool> truc(N);
for (int i = 0; i < N; i ++) truc[i] = 0;
for (int i = 0; i < N; i ++)
{
if (answer[i])
{
truc[i] = 1;
if (!test_students(truc)) answer[i] = 0;
truc[i] = 0;
}
}
}
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
| # | Verdict | Execution time | Memory | Grader output |
|---|---|---|---|---|
| 1 | Correct | 1 ms | 344 KB | Output is correct |
| # | Verdict | Execution time | Memory | Grader output |
|---|---|---|---|---|
| 1 | Correct | 9 ms | 344 KB | Output is correct |
| 2 | Correct | 9 ms | 344 KB | Output is correct |
| 3 | Correct | 10 ms | 344 KB | Output is correct |
| 4 | Correct | 9 ms | 344 KB | Output is correct |
| 5 | Correct | 10 ms | 344 KB | Output is correct |
| 6 | Correct | 12 ms | 344 KB | Output is correct |
| 7 | Correct | 13 ms | 344 KB | Output is correct |
| 8 | Correct | 10 ms | 344 KB | Output is correct |
| 9 | Correct | 13 ms | 344 KB | Output is correct |
| 10 | Correct | 6 ms | 344 KB | Output is correct |
| 11 | Correct | 8 ms | 344 KB | Output is correct |
| 12 | Correct | 8 ms | 344 KB | Output is correct |
| 13 | Correct | 9 ms | 344 KB | Output is correct |
| 14 | Correct | 8 ms | 344 KB | Output is correct |
| 15 | Correct | 8 ms | 344 KB | Output is correct |
| 16 | Correct | 9 ms | 344 KB | Output is correct |
| 17 | Correct | 1 ms | 344 KB | Output is correct |
| # | Verdict | Execution time | Memory | Grader output |
|---|---|---|---|---|
| 1 | Correct | 41 ms | 344 KB | Output is correct (P=0.001, F=15.1, Q=16.8) -> 62.05 points |
| 2 | Correct | 179 ms | 344 KB | Output is correct (P=0.005256, F=51.1, Q=72.7) -> 33.45 points |
| 3 | Correct | 862 ms | 344 KB | Output is correct (P=0.011546, F=94.9, Q=295.8) -> 9.51 points |
| 4 | Correct | 649 ms | 344 KB | Output is correct (P=0.028545, F=191.5, Q=278.2) -> 32.02 points |
| 5 | Correct | 883 ms | 344 KB | Output is correct (P=0.039856, F=246.3, Q=353.1) -> 32.91 points |
| 6 | Correct | 1245 ms | 344 KB | Output is correct (P=0.068648, F=366.2, Q=516.3) -> 34.10 points |
| 7 | Correct | 1629 ms | 344 KB | Output is correct (P=0.104571, F=490.3, Q=675.0) -> 35.90 points |
| 8 | Correct | 2121 ms | 344 KB | Output is correct (P=0.158765, F=639.1, Q=860.8) -> 37.70 points |
| 9 | Correct | 2598 ms | 344 KB | Output is correct (P=0.2, F=731.4, Q=980.9) -> 38.06 points |