제출 #1160632

#제출 시각아이디문제언어결과실행 시간메모리
1160632CyanmondCOVID tests (CEOI24_covid)C++20
100 / 100
764 ms444 KiB
#include <bits/stdc++.h> #define AOTSUKI using namespace std; constexpr bool isMultiCase = 1; // #include "angel/math/modint.hpp" using ll = long long; template <class T> constexpr int len(const T &c) { return int(std::ssize(c)); } template <class T> using V = vector<T>; template <class T> using RevPq = priority_queue<T, vector<T>, greater<T>>; constexpr char eoln = '\n'; #define L(i, l, r) for (int i = (l); i < (r); ++i) #define R(i, l, r) for (int i = (r) - 1; i >= (l); --i) #define ALL(x) (x).begin(), (x).end() #define fi first #define se second #include <cassert> #include <cstdio> #include <string> #include <vector> /// 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. using Float = long double; V<Float> opt; V<Float> opos; void init() { opt.resize(N + 2, 1ll << 60); opos.resize(N + 2, 0); opt[0] = 0; opt[1] = 0; L(i, 2, N + 2) { // split Float ngn = pow(1 - P, i); Float amin = 0; L(j, 1, i) { Float score = 1; Float up = ((1 - pow(1 - P, j)) / (1 - ngn)); // cerr << i << ' ' << j << ' ' << up << endl; score += opt[j] * up; // 見つからなかったら score += opt[i - j] * (1 - up); if (score < opt[i]) { opt[i] = score; amin = j; } } opos[i] = amin; } } std::vector<bool> find_positive() { V<bool> answer(N); L(l, -1, N) { int r = N; Float pex = 1 - pow(1 - P, N - l - 1); if (1 + pex * opt[r - l] < opt[r - l]) { V<bool> mask(N); L(i, l + 1, N) mask[i] = true; auto res = test_students(mask); if (not res) break; } while (r - l > 1) { int m = l + 1 + opos[r - l]; // cerr << m << endl; V<bool> mask(N); L(i, l + 1, m) mask[i] = true; auto res = test_students(mask); if (res) r = m - 1; else l = m - 1; } if (r == N) break; answer[r] = true; } return answer; } int main() { int T; scanf("%d %lf %d", &N, &P, &T); // You may perform any extra initialization here. P = min(P, 0.2); P = max(P, 0.001); init(); /* for (auto e : opt) cerr << e << ' '; cerr << endl; for (auto e : opos) cerr << e << ' '; cerr << endl; */ 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; }

컴파일 시 표준 에러 (stderr) 메시지

Main.cpp: In function 'bool test_students(std::vector<bool>)':
Main.cpp:50:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |     scanf(" %c", &answer);
      |     ~~~~~^~~~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:123:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  123 |     scanf("%d %lf %d", &N, &P, &T);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:147:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  147 |         scanf(" %c", &verdict);
      |         ~~~~~^~~~~~~~~~~~~~~~~
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