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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#528567 | #9162. COVID tests | Dimash# | 0 | 7ms | 3928kb | C++23 | 3.3kb | 2024-08-23 16:23:05 | 2024-08-23 16:23:05 |
answer
#include <cassert>
#include <cstdio>
#include <string>
#include <vector>
#include <bits/stdc++.h>
using namespace std;;
/// You may use:
string s;
// 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 loc = 0;
bool test_students(std::vector<bool> mask) {
if(loc) {
bool ans = false;
for(int i = 0; i < N; i++) {
if(mask[i] && s[i] == '1') {
ans = 1;
}
}
return ans;
}
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.
vector<int> ord;
bool as(int l,int r) {
vector<bool> ask(N,0);
for(int i = l;i <= min(N - 1,r);i++) {
ask[ord[i]] = 1;
}
return test_students(ask);
}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
std::vector<bool> find_positive() {
vector<bool> answer(N),ask(N,0);
ord.resize(N);
iota(ord.begin(),ord.end(),0);
shuffle(ord.begin(),ord.end(),rng);
int col = 0;
function<void(int,int)>go = [&](int l,int r) {
if(l > r) return;
if(l == r) {
col++;
answer[ord[l]] = 1;
return;
}
int mid = (l + r) >> 1;
if(as(l,mid)) {
go(l,mid);
}
if(col < 250 && as(mid+1,r)) {
go(mid+1,r);
}
};
if(P > 0.028545) go(0,N-1);
else {
int i = 0;
while(i < N) {
int l = i - 1,r = N;
while(r - l > 1) {
int mid = (l + r) >> 1;
if(as(i,mid)) {
r = mid;
} else {
l = mid;
}
}
if(r < N) {
answer[r] = 1;
i = r + 1;
} else {
break;
}
}
}
return answer;
}
int main() {
int T;
scanf("%d %lf %d", &N, &P, &T);
if(loc) cin >> s;
// 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;
}
Details
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Subtask #1:
score: 0
Wrong Answer
Test #1:
score: 0
Wrong Answer
time: 7ms
memory: 3928kb
input:
1000 0.789673 1 P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P N P P P P P P P P P N P P P P P P P P P P P P P P P P N P P P N P P P P P P P P P P P P P P P P P P P P P P P P N P P N P P P P N P P P P P P N P P P P P P N P P P P P P N P P P P P P P P P P P P P P P P P P N P P P P P P ...
output:
Q 0001000001010100110010101000100111000000110011011010000001000110100001100101100100001111000011010101100011001111110001010010000101100100011100111001101101111100111101011110110000010001110110110011110011100000100011000100100101110100101001010101001011010111111010110101111010001000100010011110000101...
result:
points 0.0 0.0 translate:wrong
Subtask #2:
score: 0
Wrong Answer
Test #18:
score: 0
Wrong Answer
time: 1ms
memory: 3756kb
input:
1000 0.001 300 N N N N N N N N N N C P N N P P P N P P P N N N N N N N N N N W
output:
Q 1000011110100101010010001101101101110101011100110011001111000001100101011111100111000100110100000010011101101111001010010110011010101000110110111010101111101000000100110000101001001011001000011010101011110010111010101111011100010000101011010000011110010001000111010010000100000001101001001111011010...
result:
points 0.0 0.0 translate:wrong