#include <cassert>
#include <cstdio>
#include <string>
#include <vector>
#include <bits/stdc++.h>
typedef int ll;
typedef long double ld;
using namespace std;
typedef pair<ll, ll> pll;
#define vc vector
const ll INF = 1e6;
vc<ll> bestp, best;
/// 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.
vc<bool> res;
void rec(ll l, ll r, bool pos) {
ll s = (r - l + 1);
if (s == 0)
return;
if (s == 1 and pos) {
res[l] = true;
return;
}
if (s == 1) {
vc<bool> mask(N, false);
mask[l] = true;
if (test_students(mask))
res[l] = true;
return;
}
ll d;
if (pos)
d = bestp[s];
else
d = best[s];
vc<bool> mask(N, false);
for (ll i = l; i < l + d; i++)
mask[i] = true;
if (test_students(mask)) {
rec(l, l + d - 1, true);
pos = false;
}
rec(l + d, r, pos);
}
std::vector<bool> find_positive() {
res.assign(N, false);
rec(0, N - 1, false);
return res;
}
void dynamic() {
vc<ld> exp(N + 1);
exp[0] = 1;
for (ll i = 1; i <= N; i++)
exp[i] = exp[i - 1] * (1 - P);
vc<ld> dpp(N + 1);
vc<ld> dp(N + 1);
dp[0] = dpp[0] = dpp[1] = 0;
dp[1] = 1;
best.assign(N + 1, 0);
bestp.assign(N + 1, 0);
for (ll i = 2; i <= N; i++) {
dp[i] = INF;
dpp[i] = INF;
for (ll j = 1; j < i; j++) {
ld x = dp[i - j] + (1 - exp[j]) * dpp[j] + 1;
ld pp = (1 - exp[j]) / (1 - exp[i]);
ld xp = pp * dp[i - j] + (1 - pp) * dpp[i - j] + pp * dpp[j] + 1;
if (x < dp[i]) {
dp[i] = x;
best[i] = j;
}
if (xp < dpp[i]) {
dpp[i] = xp;
bestp[i] = j;
}
}
}
}
int main() {
int T;
scanf("%d %lf %d", &N, &P, &T);
// You may perform any extra initialization here.
dynamic();
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:37:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
37 | scanf(" %c", &answer);
| ~~~~~^~~~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:119:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
119 | scanf("%d %lf %d", &N, &P, &T);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:136:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
136 | scanf(" %c", &verdict);
| ~~~~~^~~~~~~~~~~~~~~~~
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