Submission #871345

#	Time	Username	Problem	Language	Result	Execution time	Memory
871345		rainboy	Secret Permutation (RMI19_permutation)	C++17	62.43 / 100	13 ms	600 KiB

permutation

#include "permutation.h"
#include <vector>

using namespace std;

typedef vector<int> vi;

const int N = 256;

int abs_(int a) { return a > 0 ? a : -a; }
int min(int a, int b) { return a < b ? a : b; }

int dd[N];

void solve(int n) {
	vi ii(n);
	for (int i = 0; i < n; i++) {
		for (int h = 0; h < n; h++)
			ii[h] = (i + h) % n + 1;
		dd[i] = query(ii);
	}
	int sum = 0;
	for (int i = 0; i < n; i++)
		sum += dd[i];
	sum /= (n - 1);
	for (int i = 0; i < n; i++)
		dd[i] = sum - dd[i];
	vi pp(n);
	pp[0] = 0, pp[1] = dd[1];
	for (int i = 2; i < n; i++) {
		for (int h = 0; h < n; h++)
			ii[h] = (h < i ? i - 1 - h : h) + 1;
		pp[i] = query(ii) - (sum - dd[0]) + dd[i];
		if (abs_(pp[i] - pp[i - 1]) != dd[i])
			pp[i] = -pp[i];
	}
	int p = 0;
	for (int i = 0; i < n; i++)
		p = min(p, pp[i]);
	for (int i = 0; i < n; i++)
		pp[i] -= p - 1;
	answer(pp);
}

Compilation message (stderr)

stub.cpp: In function 'int query(int*)':
stub.cpp:15:9: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |   fscanf(stdin, "%d", &x);
      |   ~~~~~~^~~~~~~~~~~~~~~~~
stub.cpp: In function 'int main(int, char**)':
stub.cpp:48:9: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |   fscanf(stdin, "%d", &N);
      |   ~~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 10.71429 / 15
• Subtask 2: 21.56 / 35
• Subtask 3: 30.15625 / 50