| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 1078248 |
2024-08-27T14:30:41 Z |
anton |
COVID tests (CEOI24_covid) |
C++17 |
|
2067 ms |
11344 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;
int group_sz =1;
// 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.
bool test_single(int u){
vector<bool> mask(N, false);
mask[u] = true;
return test_students(mask);
}
bool test_inter(int l, int r){
vector<bool> mask(N, false);
for(int i = l; i<=r; i++){
mask[i] = true;
}
return test_students(mask);
}
int split_len[1001][1001];
double expected_turns[1001][1001];
std::vector<bool> find_positive() {
std::vector<bool> answer(N);
int total = N;
int pref = 0;
while(total>0){
if(split_len[total][pref] == 0){
answer[N-total] = true;
total --;
pref = 0;
}
else{
int len = split_len[total][pref];
bool is_one = test_inter(N-total, N-total+len-1);
if(is_one){
pref = len;
}
else{
total-=len;
if(len<pref){
pref-=len;
}
}
}
}
return answer;
}
double memo[1001];
double mpow(int deg){
return memo[deg];
}
double P_1(int len){
return 1.-mpow(len);
}
double P_none(int len){
return mpow(len);
}
void chmax(int total, int pref, int test_len, double expected){
if(expected_turns[total][pref]>expected){
split_len[total][pref] = test_len;
expected_turns[total][pref] = expected;
}
}
int main() {
int T;
scanf("%d %lf %d", &N, &P, &T);
memo[0] =1.;
for(int i =1; i<1001; i++){
memo[i] = memo[i-1] * (1.-P);
}
// You may perform any extra initialization here.
for(int total = 0; total<=N; total++){
for(int pref= 0; pref<=total; pref++){
expected_turns[total][pref] = 1e18;
}
}
expected_turns[0][0] = 0.;
for(int total = 1; total<=N; total++){
for(int pref= 1; pref<=total; pref++){
if(pref==1){
chmax(total, pref, 0, expected_turns[total-1][0]);
}
else{
for(int test_len = 1; test_len<pref; test_len++){
double p_cur = P_1(pref);
double P_left = P_1(test_len)/p_cur;
double expected = P_left * expected_turns[total][test_len] +(1-P_left) * expected_turns[total-test_len][pref-test_len] + 1.;
chmax(total, pref, test_len, expected);
}
}
}
for(int test_len = 1; test_len<=total; test_len++){
double expected= P_1(test_len) * expected_turns[total][test_len] + P_none(test_len) * expected_turns[total-test_len][0] + 1.;
chmax(total, 0, test_len, expected);
}
}
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:103:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
103 | scanf("%d %lf %d", &N, &P, &T);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:149:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
149 | 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 |
281 ms |
11048 KB |
Output is correct |
| 2 |
Correct |
281 ms |
11088 KB |
Output is correct |
| 3 |
Correct |
292 ms |
11088 KB |
Output is correct |
| 4 |
Correct |
281 ms |
11164 KB |
Output is correct |
| 5 |
Correct |
305 ms |
11088 KB |
Output is correct |
| 6 |
Correct |
294 ms |
11088 KB |
Output is correct |
| 7 |
Correct |
276 ms |
11084 KB |
Output is correct |
| 8 |
Correct |
296 ms |
11000 KB |
Output is correct |
| 9 |
Correct |
289 ms |
11092 KB |
Output is correct |
| 10 |
Correct |
286 ms |
11080 KB |
Output is correct |
| 11 |
Correct |
285 ms |
11008 KB |
Output is correct |
| 12 |
Correct |
289 ms |
11200 KB |
Output is correct |
| 13 |
Correct |
280 ms |
11088 KB |
Output is correct |
| 14 |
Correct |
282 ms |
11340 KB |
Output is correct |
| 15 |
Correct |
286 ms |
10996 KB |
Output is correct |
| 16 |
Correct |
304 ms |
11000 KB |
Output is correct |
| 17 |
Correct |
285 ms |
11088 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
326 ms |
11088 KB |
Output is correct (P=0.001, F=15.1, Q=10.8) -> 90.00 points |
| 2 |
Correct |
415 ms |
11344 KB |
Output is correct (P=0.005256, F=51.1, Q=46.3) -> 90.00 points |
| 3 |
Correct |
549 ms |
11088 KB |
Output is correct (P=0.011546, F=94.9, Q=90.5) -> 90.00 points |
| 4 |
Correct |
808 ms |
11088 KB |
Output is correct (P=0.028545, F=191.5, Q=187.7) -> 90.00 points |
| 5 |
Correct |
909 ms |
11088 KB |
Output is correct (P=0.039856, F=246.3, Q=243.7) -> 90.00 points |
| 6 |
Correct |
1176 ms |
11088 KB |
Output is correct (P=0.068648, F=366.2, Q=364.2) -> 90.00 points |
| 7 |
Correct |
1528 ms |
11088 KB |
Output is correct (P=0.104571, F=490.3, Q=488.2) -> 90.00 points |
| 8 |
Correct |
1775 ms |
11220 KB |
Output is correct (P=0.158765, F=639.1, Q=633.1) -> 90.00 points |
| 9 |
Correct |
2067 ms |
11044 KB |
Output is correct (P=0.2, F=731.4, Q=729.3) -> 90.00 points |
