| # | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1090044 | 2024-09-17T16:03:22 Z | KALARRY | COVID tests (CEOI24_covid) | C++14 | 3648 ms | 344 KB |
#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.
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> find_positive() {
std::vector<bool> answer(N);
vector<bool> mask;
int total_pos = floor(N*P);
int rem = total_pos;
for(int i = 0 ; i < N ; i++)
mask.push_back(false);
int pos = 0;
while(pos < N)
{
int reach = N-1;
for(int b = (N - pos - 1)/max(1,rem) ; b >= 1 ; b/=2)
while(pos + b <= reach)
{
for(int i = pos ; i <= pos + b ; i++)
mask[i] = true;
bool res = test_students(mask);
for(int i = pos ; i <= pos + b ; i++)
mask[i] = false;
if(!res)
{
for(int i = pos ; i <= pos + b ; i++)
answer[i] = false;
pos += (b+1);
}
else
{
reach = pos + b -1;
break;
}
}
mask[pos] = true;
bool res = test_students(mask);
answer[pos] = res;
mask[pos] = false;
pos++;
rem--;
}
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 | Incorrect | 19 ms | 344 KB | Output isn't correct |
| 2 | Halted | 0 ms | 0 KB | - |
| # | Verdict | Execution time | Memory | Grader output |
|---|---|---|---|---|
| 1 | Correct | 41 ms | 344 KB | Output is correct (P=0.001, F=15.1, Q=16.1) -> 71.15 points |
| 2 | Correct | 157 ms | 344 KB | Output is correct (P=0.005256, F=51.1, Q=71.0) -> 35.19 points |
| 3 | Correct | 345 ms | 344 KB | Output is correct (P=0.011546, F=94.9, Q=140.7) -> 30.71 points |
| 4 | Correct | 769 ms | 344 KB | Output is correct (P=0.028545, F=191.5, Q=307.7) -> 26.26 points |
| 5 | Correct | 985 ms | 344 KB | Output is correct (P=0.039856, F=246.3, Q=418.6) -> 23.70 points |
| 6 | Correct | 1573 ms | 344 KB | Output is correct (P=0.068648, F=366.2, Q=657.3) -> 21.53 points |
| 7 | Correct | 2159 ms | 344 KB | Output is correct (P=0.104571, F=490.3, Q=920.4) -> 19.96 points |
| 8 | Correct | 3028 ms | 344 KB | Output is correct (P=0.158765, F=639.1, Q=1288.8) -> 17.76 points |
| 9 | Correct | 3648 ms | 344 KB | Output is correct (P=0.2, F=731.4, Q=1535.5) -> 16.67 points |