Submission #1058511

#	Time	Username	Problem	Language	Result	Execution time	Memory
1058511		rainboy	COVID tests (CEOI24_covid)	C11	0 / 100	5 ms	344 KiB

Main

#include <stdio.h>
#include <string.h>

#define N	1000

int min(int a, int b) { return a < b ? a : b; }

unsigned int Z = 12345;

int rand_() {
	return (Z *= 3) >> 1;
}

int n, m; double p;

int query(int *ii, int k) {
	static char cc[N + 1], s[2];
	int h;

	memset(cc, '0', n * sizeof *cc);
	for (h = 0; h < k; h++)
		cc[ii[h]] = '1';
	printf("Q %s\n", cc), fflush(stdout);
	scanf("%s", s);
	return s[0] == 'P';
}

void shuffle(int *ii, int n) {
	int h, h_, tmp;

	for (h = 0; h < n; h++) {
		h_ = rand_() % (h + 1);
		tmp = ii[h], ii[h] = ii[h_], ii[h_] = tmp;
	}
}

int main() {
	int t;

	scanf("%d%lf%d", &n, &p, &t), m = 1 / p;
	while (t--) {
		static char cc[N + 1];
		static int ii[N];
		int n_, n__, h, i, l, r, lower, upper;

		memset(cc, '0', n * sizeof *cc), cc[n] = 0;
		if (t == 1) {
			for (i = 0; i < n; i++) {
				ii[0] = i;
				if (query(ii, 1))
					cc[i] = '1';
			}
		} else {
			n_ = 0;
			for (i = 0; i < n; i++)
				ii[n_++] = i;
			while (n_ > 0) {
				shuffle(ii, n_);
				n__ = 0;
				for (l = 0; l + m <= n_; l += m) {
					r = min(l + m, n_);
					if (query(ii + l, r - l)) {
						lower = l, upper = r;
						while (upper - lower > 1) {
							h = (lower + upper) / 2;
							if (query(ii + l, h - l))
								upper = h;
							else
								lower = h;
						}
						cc[ii[lower]] = '1';
						for (h = lower + 1; h < r; h++)
							ii[n__++] = ii[h];
					}
				}
				n_ = n__;
			}
		}
		printf("A %s\n", cc), fflush(stdout);
		scanf("%*s");
	}
	return 0;
}

Compilation message (stderr)

Main.c: In function 'query':
Main.c:24:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |  scanf("%s", s);
      |  ^~~~~~~~~~~~~~
Main.c: In function 'main':
Main.c:40:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |  scanf("%d%lf%d", &n, &p, &t), m = 1 / p;
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.c:80:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   80 |   scanf("%*s");
      |   ^~~~~~~~~~~~

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