Submission #1058712

#	Time	Username	Problem	Language	Result	Execution time	Memory
1058712		rainboy	COVID tests (CEOI24_covid)	C11	59.43 / 100	1316 ms	400 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 l, int r) {
	static char cc[N + 1], s[2];

	memset(cc, '0', n * sizeof *cc), memset(cc + l, '1', (r - l) * sizeof *cc);
	printf("Q %s\n", cc), fflush(stdout);
	scanf("%s", s);
	return s[0] == 'P';
}

int main() {
	int t, subtask;

	scanf("%d%lf%d", &n, &p, &t), m = 1 / p * 2, subtask = t == 1 ? 1 : 2;
	while (t--) {
		static char cc[N + 1];
		int i, l, r, lower, upper;

		memset(cc, '0', n * sizeof *cc), cc[n] = 0;
		if (subtask == 1) {
			for (i = 0; i < n; i++)
				if (query(i, i + 1))
					cc[i] = '1';
		} else {
			l = 0;
			while (l < n) {
				r = min(l + m, n);
				if (!query(l, r)) {
					l = r;
					continue;
				}
				lower = l, upper = r;
				while (upper - lower > 1) {
					i = (lower + upper) / 2;
					if (query(l, i))
						upper = i;
					else
						lower = i;
				}
				cc[lower] = '1', l = lower + 1;
			}
		}
		printf("A %s\n", cc), fflush(stdout);
		scanf("%*s");
	}
	return 0;
}

Compilation message (stderr)

Main.c: In function 'query':
Main.c:21:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   21 |  scanf("%s", s);
      |  ^~~~~~~~~~~~~~
Main.c: In function 'main':
Main.c:28:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |  scanf("%d%lf%d", &n, &p, &t), m = 1 / p * 2, subtask = t == 1 ? 1 : 2;
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.c:58:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   58 |   scanf("%*s");
      |   ^~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 10 / 10
• Subtask 2: 49.42999999800001 / 90