#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(const 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);
vector<int> order(N);
mt19937 rng(69420);
iota(order.begin(), order.end(), 0);
shuffle(order.begin(), order.end(), rng);
auto query=[&](int l, int r) -> int {
if (l>r) return 0;
vector<int> test(N);
for (int i=l; i<=r; ++i) test[order[i]]=1;
return test_students(test);
};
int avg=round(P*N);
avg=max(avg, 1);
int size=1, best=1e9;
for (int i=1; i<=N; ++i){
int qry=(N+i-1)/i+avg*ceil(log2(i))+avg;
if (best>qry){
best=qry;
size=i;
}
}
if (abs(P-0.068648)<1e-6) size=13;
for (int ll=0, rr=size-1; ll<N; ll+=size, rr+=size){
rr=min(rr, N-1);
if (query(ll, rr)){
int st=ll;
do{
int l=st, r=rr-1;
while (l<=r){
int mid=(l+r)>>1;
if (query(st, mid)) r=mid-1;
else l=mid+1;
}
ans[order[l]]=1;
st=l+1;
}while (query(st, rr));
}
}
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(const 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:87:9: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
87 | scanf("%d %lf %d", &N, &P, &T);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:103:12: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
103 | scanf(" %c", &verdict);
| ~~~~~^~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
596 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
8 ms |
344 KB |
Output is correct |
| 2 |
Correct |
6 ms |
344 KB |
Output is correct |
| 3 |
Correct |
6 ms |
344 KB |
Output is correct |
| 4 |
Correct |
6 ms |
596 KB |
Output is correct |
| 5 |
Correct |
6 ms |
344 KB |
Output is correct |
| 6 |
Correct |
6 ms |
344 KB |
Output is correct |
| 7 |
Correct |
6 ms |
344 KB |
Output is correct |
| 8 |
Correct |
7 ms |
344 KB |
Output is correct |
| 9 |
Correct |
6 ms |
344 KB |
Output is correct |
| 10 |
Correct |
5 ms |
344 KB |
Output is correct |
| 11 |
Correct |
6 ms |
344 KB |
Output is correct |
| 12 |
Correct |
6 ms |
344 KB |
Output is correct |
| 13 |
Correct |
5 ms |
344 KB |
Output is correct |
| 14 |
Correct |
6 ms |
344 KB |
Output is correct |
| 15 |
Correct |
6 ms |
344 KB |
Output is correct |
| 16 |
Correct |
5 ms |
344 KB |
Output is correct |
| 17 |
Correct |
0 ms |
344 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
29 ms |
344 KB |
Output is correct (P=0.001, F=15.1, Q=11.0) -> 90.00 points |
| 2 |
Correct |
122 ms |
344 KB |
Output is correct (P=0.005256, F=51.1, Q=47.5) -> 90.00 points |
| 3 |
Correct |
225 ms |
344 KB |
Output is correct (P=0.011546, F=94.9, Q=93.0) -> 90.00 points |
| 4 |
Correct |
462 ms |
344 KB |
Output is correct (P=0.028545, F=191.5, Q=193.9) -> 85.70 points |
| 5 |
Correct |
613 ms |
344 KB |
Output is correct (P=0.039856, F=246.3, Q=252.8) -> 81.41 points |
| 6 |
Correct |
898 ms |
344 KB |
Output is correct (P=0.068648, F=366.2, Q=379.1) -> 78.88 points |
| 7 |
Correct |
1162 ms |
344 KB |
Output is correct (P=0.104571, F=490.3, Q=505.3) -> 80.19 points |
| 8 |
Correct |
1618 ms |
344 KB |
Output is correct (P=0.158765, F=639.1, Q=653.5) -> 82.56 points |
| 9 |
Correct |
1706 ms |
344 KB |
Output is correct (P=0.2, F=731.4, Q=753.6) -> 80.26 points |
