| # | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1119880 | 2024-11-27T14:29:57 Z | Tenis0206 | COVID tests (CEOI24_covid) | C++11 | 4739 ms | 512 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;
// 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';
}
/// 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.
std::vector<bool> answer;
bool my_test_students(int st, int dr)
{
vector<bool> mask(N);
for(int i=st; i<=dr; i++)
{
mask[i] = true;
}
return test_students(mask);
}
void divide(int st, int dr)
{
if(st == dr)
{
answer[st] = true;
return;
}
int mij = (st + dr) >> 1;
bool ok_st = my_test_students(st, mij);
bool ok_dr = my_test_students(mij + 1, dr);
if(ok_st)
{
divide(st, mij);
}
if(ok_dr)
{
divide(mij + 1, dr);
}
}
void find_positive()
{
if(P < 2)
{
int poz = 0;
while(poz < N)
{
int st = poz;
int dr = min(N - 1, (int)(poz + 1.5 * (1 / P)));
int rez = -1;
while(st <= dr)
{
int mij = (st + dr) >> 1;
bool ok = my_test_students(poz, mij);
if(ok)
{
rez = mij;
dr = mij - 1;
}
else
{
st = mij + 1;
}
}
if(rez == -1)
{
st = poz;
dr = N - 1;
rez = -1;
while(st <= dr)
{
int mij = (st + dr) >> 1;
bool ok = my_test_students(poz, mij);
if(ok)
{
rez = mij;
dr = mij - 1;
}
else
{
st = mij + 1;
}
}
if(rez == -1)
{
break;
}
}
answer[rez] = true;
poz = rez + 1;
}
}
else
{
vector<bool> mask(N);
for(int i=0; i<N; i++)
{
mask[i] = false;
}
for(int i=0; i<N; i++)
{
mask[i] = true;
bool ok = test_students(mask);
answer[i] = ok;
mask[i] = false;
}
}
}
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++)
{
answer.resize(N);
for(int j=0; j<N; j++)
{
answer[j] = false;
}
find_positive();
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 | 336 KB | Output is correct |
| # | Verdict | Execution time | Memory | Grader output |
|---|---|---|---|---|
| 1 | Correct | 26 ms | 336 KB | Output is correct |
| 2 | Correct | 22 ms | 336 KB | Output is correct |
| 3 | Correct | 20 ms | 336 KB | Output is correct |
| 4 | Correct | 33 ms | 336 KB | Output is correct |
| 5 | Correct | 18 ms | 336 KB | Output is correct |
| 6 | Correct | 22 ms | 336 KB | Output is correct |
| 7 | Correct | 21 ms | 336 KB | Output is correct |
| 8 | Correct | 23 ms | 512 KB | Output is correct |
| 9 | Correct | 33 ms | 336 KB | Output is correct |
| 10 | Correct | 17 ms | 336 KB | Output is correct |
| 11 | Correct | 24 ms | 336 KB | Output is correct |
| 12 | Correct | 19 ms | 336 KB | Output is correct |
| 13 | Correct | 25 ms | 336 KB | Output is correct |
| 14 | Correct | 22 ms | 336 KB | Output is correct |
| 15 | Correct | 20 ms | 336 KB | Output is correct |
| 16 | Correct | 19 ms | 336 KB | Output is correct |
| 17 | Correct | 1 ms | 336 KB | Output is correct |
| # | Verdict | Execution time | Memory | Grader output |
|---|---|---|---|---|
| 1 | Correct | 185 ms | 336 KB | Output is correct (P=0.001, F=15.1, Q=27.3) -> 21.27 points |
| 2 | Correct | 357 ms | 336 KB | Output is correct (P=0.005256, F=51.1, Q=64.4) -> 44.09 points |
| 3 | Correct | 648 ms | 336 KB | Output is correct (P=0.011546, F=94.9, Q=115.1) -> 48.61 points |
| 4 | Correct | 1342 ms | 336 KB | Output is correct (P=0.028545, F=191.5, Q=227.3) -> 51.49 points |
| 5 | Correct | 1718 ms | 336 KB | Output is correct (P=0.039856, F=246.3, Q=298.4) -> 48.75 points |
| 6 | Correct | 2512 ms | 336 KB | Output is correct (P=0.068648, F=366.2, Q=449.2) -> 47.20 points |
| 7 | Correct | 3326 ms | 336 KB | Output is correct (P=0.104571, F=490.3, Q=595.8) -> 48.37 points |
| 8 | Correct | 4428 ms | 336 KB | Output is correct (P=0.158765, F=639.1, Q=796.7) -> 45.31 points |
| 9 | Execution timed out | 4739 ms | 336 KB | Time limit exceeded (wall clock) |
| 10 | Halted | 0 ms | 0 KB | - |