# | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
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1090057 | 2024-09-17T16:29:45 Z | KALARRY | COVID tests (CEOI24_covid) | C++14 | 7000 ms | 596 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; int expect_to_reach = 0; double val = (1-P); while(val * (1-P) >= 0.5) { expect_to_reach++; val *= (1-P); } while(pos < N) { int reach = N-1; int b = expect_to_reach; double extra = 1; while(b > 0) { while(pos + b <= reach) { double Prob_all_positve = 1/extra; for(int i = pos ; i <= pos + b ; i++) { Prob_all_positve *= (1 - P); if(Prob_all_positve < 0.5) { b = i - pos; break; } } 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 { extra = (1 - Prob_all_positve); reach = pos + b -1; break; } } b--; } 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
# | 결과 | 실행 시간 | 메모리 | Grader output |
---|---|---|---|---|
1 | Correct | 1 ms | 344 KB | Output is correct |
# | 결과 | 실행 시간 | 메모리 | Grader output |
---|---|---|---|---|
1 | Correct | 6 ms | 344 KB | Output is correct |
2 | Correct | 6 ms | 344 KB | Output is correct |
3 | Correct | 8 ms | 596 KB | Output is correct |
4 | Correct | 6 ms | 344 KB | Output is correct |
5 | Correct | 6 ms | 348 KB | Output is correct |
6 | Correct | 6 ms | 344 KB | Output is correct |
7 | Correct | 6 ms | 344 KB | Output is correct |
8 | Correct | 6 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 | 7 ms | 348 KB | Output is correct |
13 | Correct | 8 ms | 344 KB | Output is correct |
14 | Correct | 7 ms | 344 KB | Output is correct |
15 | Correct | 6 ms | 344 KB | Output is correct |
16 | Correct | 7 ms | 344 KB | Output is correct |
17 | Execution timed out | 7067 ms | 344 KB | Time limit exceeded |
18 | Halted | 0 ms | 0 KB | - |
# | 결과 | 실행 시간 | 메모리 | Grader output |
---|---|---|---|---|
1 | Incorrect | 589 ms | 344 KB | Incorrect |
2 | Halted | 0 ms | 0 KB | - |