#include <cassert>
#include <cstdio>
#include <string>
#include <vector>
#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.
int test_students(std::vector<int> 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<int> find_positive() {
vector<int> ans(N);
auto query=[&](int l, int r) -> int {
vector<int> test(N);
fill(test.begin()+l, test.begin()+r+1, 1);
return test_students(test);
};
auto solve=[&](auto &&self, int l, int r) -> void {
if (l==r){
ans[l]=1;
return;
}
int mid=(l+r)>>1;
if (query(l, mid)){
self(self, l, mid);
if (query(mid+1, r)) self(self, mid+1, r);
}else self(self, mid+1, r);
};
solve(solve, 0, N-1);
return ans;
}
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<int> 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 'int test_students(std::vector<int>)':
Main.cpp:33:9: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
33 | scanf(" %c", &answer);
| ~~~~~^~~~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:67:9: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
67 | scanf("%d %lf %d", &N, &P, &T);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:83:12: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
83 | 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 |
16 ms |
344 KB |
Output is correct |
3 |
Correct |
14 ms |
340 KB |
Output is correct |
4 |
Correct |
13 ms |
344 KB |
Output is correct |
5 |
Correct |
13 ms |
344 KB |
Output is correct |
6 |
Correct |
16 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 |
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 |
12 ms |
344 KB |
Output is correct |
14 |
Correct |
10 ms |
344 KB |
Output is correct |
15 |
Correct |
9 ms |
344 KB |
Output is correct |
16 |
Correct |
19 ms |
344 KB |
Output is correct |
17 |
Incorrect |
0 ms |
344 KB |
translate:wrong |
18 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
344 KB |
translate:wrong |
2 |
Halted |
0 ms |
0 KB |
- |