Submission #1044493

#	Time	Username	Problem	Language	Result	Execution time	Memory
1044493		c2zi6	COVID tests (CEOI24_covid)	C++14	36.45 / 100	2080 ms	596 KiB

Main

#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define replr(i, a, b) for (int i = int(a); i <= int(b); ++i)
#define reprl(i, a, b) for (int i = int(a); i >= int(b); --i)
#define rep(i, n) for (int i = 0; i < int(n); ++i)
#define mkp(a, b) make_pair(a, b)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPI;
typedef vector<VI> VVI;
typedef vector<VVI> VVVI;
typedef vector<VPI> VVPI;
typedef pair<ll, ll> PLL;
typedef vector<ll> VL;
typedef vector<PLL> VPL;
typedef vector<VL> VVL;
typedef vector<VVL> VVVL;
typedef vector<VPL> VVPL;
template<class T> T setmax(T& a, T b) {if (a < b) return a = b; return a;}
template<class T> T setmin(T& a, T b) {if (a < b) return a; return a = b;}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template<typename T>
using indset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef vector<bool> VB;
 
int N;
double P;
VB iskakan;
 
bool test_students(std::vector<bool> mask) {
    /*rep(i, N) if (mask[i] && iskakan[i]) return true;*/
    /*return false;*/
 
    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';
}
 
VB find_positive() {
    int n = N;
    if (P >= 0.2) {
        VB answer(n);
        rep(i, n) {
            VB mask(n);
            mask[i] = true;
            if (test_students(mask)) answer[i] = true;
        }
        return answer;
    } else {
        /*if (true) {*/
        /*    iskakan = VB(n);*/
        /*    string s;*/
        /*    cin >> s;*/
        /*    rep(i, n) iskakan[i] = (s[i] == '1');*/
        /*}*/
        VB answer(n);
        int cnt = (n / int(1000 * P));
        /*VPI seg;*/
        /*for (int l = 0; l < n;) {*/
        /*    if (l+cnt > n-1) {*/
        /*        seg.pb({l, n-1});*/
        /*        break;*/
        /*    }*/
        /*    seg.pb({l, l+cnt});*/
        /*    l = l+cnt+1;*/
        /*}*/
        /*seg.pb({0, 500});*/
        /*seg.pb({501, n-1});*/
        /*for (auto[L, R] : seg) {*/
        /*    cout << "SEGMENT " << L << ".." << R << endl;*/
        /*}*/

        /*for (auto[L, R] : seg) {*/
        int L = 0, R = min(n-1, L+cnt);
        while (true) {
            /*cout << "PROCESSING SEGMENT " << L << ".." << R << endl;*/
            /*int last = L-1;*/
            /*while (true) {*/
                int l = L-1, r = R+1;
                while (l + 1 < r) {
                    int m = (l + r) / 2;
                    VB query(n);
                    replr(i, 0, m) query[i] = (true && !answer[i]);
                    bool f = test_students(query);
                    if (f) r = m;
                    else l = m;
                }
                if (r != R+1) {
                    answer[r] = true;
                    L = r+1;
                    R = min(n-1, L+cnt);
                } else {
                    L = R+1;
                    R = min(n-1, L+cnt);
                }
            if (L > n-1) break;
        }
            /*}*/
        /*}*/
        return answer;
    }
    return VB();
}
 
int main() {
    int T;
    scanf("%d %lf %d", &N, &P, &T);
    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 (stderr)

Main.cpp: In function 'bool test_students(std::vector<bool>)':
Main.cpp:49:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |     scanf(" %c", &answer);
      |     ~~~~~^~~~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:121:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  121 |     scanf("%d %lf %d", &N, &P, &T);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:131:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  131 |         scanf(" %c", &verdict);
      |         ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 0 / 10
• Subtask 2: 36.45 / 90