#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.
void rectest(int L, int R, vector<bool> &test, vector<bool> &answer)
{
if (test_students(test) == 0)
return;
if (L == R)
{
answer[L] = 1;
return;
}
int m = (L + R) / 2;
for (int i = L; i <= m; i++)
test[i] = 0;
rectest(m + 1, R, test, answer);
for (int i = L; i <= m; i++)
test[i] = 1;
for (int i = m + 1; i <= R; i++)
test[i] = 0;
rectest(L, m, test, answer);
}
std::vector<bool> find_positive()
{
std::vector<bool> answer(N);
vector<bool> left(N, 0);
int div = ceil((double)1 / P);
div *= 2;
vector<bool> test(N, 0);
int L = 0, R = div - 1;
if (P > 0.2)
{
test.assign(N, 1);
rectest(0, N - 1, test, answer);
return answer;
}
while (true)
{
R = min(R, N - 1);
L = min(L, N - 1);
for (int i = L; i <= R; i++)
left[i] = 1;
while (test_students(left))
{
int L2 = L, R2 = R;
while (L2 < R2)
{
int m = (L2 + R2) / 2;
for (int i = L2; i <= m; i++)
test[i] = (1 & left[i]);
bool b = test_students(test);
for (int i = L2; i <= m; i++)
test[i] = 0;
if (b)
R2 = m;
else
L2 = m + 1;
}
answer[L2] = 1;
left[L2] = 0;
}
for (int i = L; i <= R; i++)
left[i] = 0;
if (R == N - 1)
break;
L += div, R += div;
}
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:28:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
28 | scanf(" %c", &answer);
| ~~~~~^~~~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:108:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
108 | scanf("%d %lf %d", &N, &P, &T);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:125:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
125 | scanf(" %c", &verdict);
| ~~~~~^~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
344 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
12 ms |
344 KB |
Output is correct |
| 2 |
Correct |
10 ms |
344 KB |
Output is correct |
| 3 |
Correct |
11 ms |
344 KB |
Output is correct |
| 4 |
Correct |
13 ms |
344 KB |
Output is correct |
| 5 |
Correct |
12 ms |
344 KB |
Output is correct |
| 6 |
Correct |
12 ms |
344 KB |
Output is correct |
| 7 |
Correct |
10 ms |
344 KB |
Output is correct |
| 8 |
Correct |
11 ms |
344 KB |
Output is correct |
| 9 |
Correct |
11 ms |
344 KB |
Output is correct |
| 10 |
Correct |
5 ms |
344 KB |
Output is correct |
| 11 |
Correct |
9 ms |
344 KB |
Output is correct |
| 12 |
Correct |
9 ms |
344 KB |
Output is correct |
| 13 |
Correct |
9 ms |
344 KB |
Output is correct |
| 14 |
Correct |
11 ms |
344 KB |
Output is correct |
| 15 |
Correct |
10 ms |
344 KB |
Output is correct |
| 16 |
Correct |
12 ms |
344 KB |
Output is correct |
| 17 |
Execution timed out |
4192 ms |
344 KB |
Time limit exceeded (wall clock) |
| 18 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
26 ms |
344 KB |
Output is correct (P=0.001, F=15.1, Q=11.0) -> 90.00 points |
| 2 |
Correct |
117 ms |
344 KB |
Output is correct (P=0.005256, F=51.1, Q=51.2) -> 89.30 points |
| 3 |
Correct |
250 ms |
344 KB |
Output is correct (P=0.011546, F=94.9, Q=102.7) -> 67.73 points |
| 4 |
Correct |
572 ms |
344 KB |
Output is correct (P=0.028545, F=191.5, Q=219.2) -> 57.01 points |
| 5 |
Correct |
722 ms |
596 KB |
Output is correct (P=0.039856, F=246.3, Q=290.6) -> 52.34 points |
| 6 |
Correct |
1077 ms |
344 KB |
Output is correct (P=0.068648, F=366.2, Q=442.3) -> 49.15 points |
| 7 |
Correct |
1544 ms |
344 KB |
Output is correct (P=0.104571, F=490.3, Q=616.7) -> 44.31 points |
| 8 |
Correct |
1875 ms |
344 KB |
Output is correct (P=0.158765, F=639.1, Q=836.5) -> 40.26 points |
| 9 |
Correct |
2467 ms |
344 KB |
Output is correct (P=0.2, F=731.4, Q=984.2) -> 37.77 points |
