답안 #1040863

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1040863 2024-08-01T10:59:15 Z elazarkoren COVID tests (CEOI24_covid) C++17
78.05 / 100
3707 ms 1636 KB
#include <bits/stdc++.h>
#define x first
#define y second
#define all(v) v.begin(), v.end()
#define chkmin(a, b) a = min(a, b)
#define chkmax(a, b) a = max(a, b)
using namespace std;
typedef long long ll;
typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef pair<ll, ll> pii;
typedef vector<pii> vii;
typedef vector<bool> vb;
/// 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.

map<vb, bool> mp;

bool test_students(std::vector<bool> mask) {
    if (mp.count(mask)) return mp[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 mp[mask] = (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.

mt19937 rng(time(0));

int mrand(int l, int r) {
    return uniform_int_distribution<int>(l, r)(rng);
}

int FindNext(int l, int r, vi &ind) {
    vb mask(n);
    for (int i = l; i < r; i++) mask[ind[i]] = 1;
    if (!test_students(mask)) return r;
    for (int i = l; i < r; i++) mask[ind[i]] = 0;
    int begin = l + 1, end = r;
    while (begin < end) {
        int mid = (begin + end) >> 1;
        for (int i = l; i < mid; i++) mask[ind[i]] = 1;
        if (test_students(mask)) end = mid;
        else begin = mid + 1;
        for (int i = l; i < mid; i++) mask[ind[i]] = 0;
    }
    return end - 1;
}

void Solve(int l, int r, vi &ind, vb &ans) {
    while (l < r) {
        int nx = FindNext(l, r, ind);
        ans[nx] = 1;
        l = nx + 1;
    }
}

int cnt = 0;

void Solve2(int l, int r, vb &ans) {
    if (l + 1 == r) {
        cnt++;
        ans[l] = 1;
        return;
    }
    if (mrand(0, 1)) {
        vb test(n);
        int mid = (l + r) >> 1;
        fill(test.begin() + l, test.begin() + mid, 1);
        bool b = test_students(test);
        fill(test.begin() + l, test.begin() + mid, 0);
        if (!b) {
            Solve2(mid, r, ans);
            return;
        }
        Solve2(l, mid, ans);
        if (cnt > 2 * n * P) return;
        fill(test.begin() + mid, test.begin() + r, 1);
        b = test_students(test);
        fill(test.begin() + mid, test.begin() + r, 0);
        if (b) Solve2(mid, r, ans);
    } else {
        vb test(n);
        int mid = (l + r) >> 1;
        fill(test.begin() + mid, test.begin() + r, 1);
        bool b = test_students(test);
        fill(test.begin() + mid, test.begin() + r, 0);
        if (!b) {
            Solve2(l, mid, ans);
            return;
        }
        Solve2(mid, r, ans);
        if (cnt > 2 * n * P) return;
        fill(test.begin() + l, test.begin() + mid, 1);
        b = test_students(test);
        fill(test.begin() + l, test.begin() + mid, 0);
        if (b) Solve2(l, mid, ans);
    }
}

vb find_positive() {
    mp.clear();
//    if (P > 0.16) {
//        vb ans(n);
//        vb mask(n);
//        for (int i = 0; i < n; i += 2) {
//            mask[i] = mask[i + 1] = 1;
//            bool b = test_students(mask);
//            mask[i] = mask[i + 1] = 0;
//            if (b) {
//                int j = i, k = i + 1;
//                if (mrand(0, 1)) swap(j, k);
//                mask[j] = 1;
//                ans[j] = test_students(mask);
//                mask[j] = 0, mask[k]=  1;
//                if (!ans[j]) ans[k] = 1;
//                else ans[k] = test_students(mask);
//                mask[k] = 0;
//            }
//        }
//        return ans;
//    }
//    if (P < 0.05) {
        vb ans(n);
        vi ind(n);
        iota(all(ind), 0);
        while (!ind.empty()) {
            vi nx;
            shuffle(all(ind), rng);
            int m = ind.size();
            int blocks = min<int>(m, ceil(m * P * 2));
            int len = (m + blocks - 1) / blocks;
            for (int i = 0; i < m; i += len) {
//            Solve(i, min(i + len, n), ans);
                int l = i, r = min(i + len, m);
                int j = FindNext(l, r, ind);
                if (j < r) ans[ind[j++]] = 1;
                for (int k = j; k < r; k++) nx.push_back(ind[k]);
            }
            swap(ind, nx);
        }
        return ans;
//    }


//    vb ans(n);
//    cnt = 0;
//    Solve2(0, n, ans);
//    return ans;

//    int block = 1000;
//    for (int i = 0; i < n; i += block) Solve(i, i + block, ans);

//    Solve(0, n, answer);
//    vb test(n);
//    for (int i = 0; i < n; i++) {
//        test[i] = 1;
//        answer[i] = test_students(test);
//        test[i] = 0;
//    }
//    return ans;
}

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++) {
        vb answer = find_positive();
        assert(answer.size() == (size_t)n);

        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

Main.cpp: In function 'bool test_students(std::vector<bool>)':
Main.cpp:41:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |     scanf(" %c", &answer);
      |     ~~~~~^~~~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:190:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  190 |     scanf("%d %lf %d", &n, &P, &T);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:206:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  206 |         scanf(" %c", &verdict);
      |         ~~~~~^~~~~~~~~~~~~~~~~
# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 344 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 632 KB Output is correct
2 Correct 22 ms 520 KB Output is correct
3 Correct 21 ms 572 KB Output is correct
4 Correct 21 ms 952 KB Output is correct
5 Correct 18 ms 600 KB Output is correct
6 Correct 20 ms 600 KB Output is correct
7 Correct 18 ms 480 KB Output is correct
8 Correct 20 ms 600 KB Output is correct
9 Correct 18 ms 536 KB Output is correct
10 Correct 9 ms 600 KB Output is correct
11 Correct 21 ms 736 KB Output is correct
12 Correct 17 ms 600 KB Output is correct
13 Correct 18 ms 852 KB Output is correct
14 Correct 20 ms 1636 KB Output is correct
15 Correct 18 ms 600 KB Output is correct
16 Correct 18 ms 592 KB Output is correct
17 Runtime error 0 ms 344 KB Execution killed with signal 8
18 Halted 0 ms 0 KB -
# 결과 실행 시간 메모리 Grader output
1 Correct 31 ms 344 KB Output is correct (P=0.001, F=15.1, Q=10.9) -> 90.00 points
2 Correct 127 ms 448 KB Output is correct (P=0.005256, F=51.1, Q=47.6) -> 90.00 points
3 Correct 256 ms 472 KB Output is correct (P=0.011546, F=94.9, Q=92.9) -> 90.00 points
4 Correct 577 ms 732 KB Output is correct (P=0.028545, F=191.5, Q=191.7) -> 89.63 points
5 Correct 798 ms 492 KB Output is correct (P=0.039856, F=246.3, Q=249.8) -> 85.16 points
6 Correct 1364 ms 592 KB Output is correct (P=0.068648, F=366.2, Q=366.4) -> 89.80 points
7 Correct 2069 ms 596 KB Output is correct (P=0.104571, F=490.3, Q=506.1) -> 79.72 points
8 Correct 2875 ms 580 KB Output is correct (P=0.158765, F=639.1, Q=634.2) -> 90.00 points
9 Correct 3707 ms 616 KB Output is correct (P=0.2, F=731.4, Q=759.4) -> 78.05 points