Submission #1134508

#	Time	Username	Problem	Language	Result	Execution time	Memory
1134508		Nurislam	COVID tests (CEOI24_covid)	C++20	15.85 / 100	1152 ms	408 KiB

Main

#include <bits/stdc++.h>
using namespace std;
  
//#define int long long
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define ff first
#define ss second
#define pb push_back

int n;
double P;
bool tst(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';
}

std::vector<bool> find_positive() {
	vector<bool> ans(n, 0);
	
	auto dfs = [&](auto dfs, int l, int r) -> void{
		if(l == r){
			ans[l] = 1;
			return;
		};
		int m = (l+r)>>1;
		vector<bool> lef(n, 0);
		for(int i = l; i <= m; i++)lef[i] = 1;
		if(tst(lef))dfs(dfs, l, m);
		vector<bool> rig(n, 0);
		for(int i = m+1; i <= r; i++)rig[i] = 1;
		if(tst(rig))dfs(dfs, m+1, r);
	};
	int bl = 33;
	for(int i = 0; i < n; i += bl){
		int l = i, r = i+bl-1;
		dfs(dfs, l, r);
	}
	
	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++) {
        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 tst(std::vector<bool>)':
Main.cpp:24:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |     scanf(" %c", &answer);
      |     ~~~~~^~~~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:55:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   55 |     scanf("%d %lf %d", &n, &P, &T);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:71:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   71 |         scanf(" %c", &verdict);
      |         ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 10 / 10
• Subtask 2: 5.85 / 90