Submission #685441

#	Time	Username	Problem	Language	Result	Execution time	Memory
685441		annie2018	Secret Permutation (RMI19_permutation)	C++17	100 / 100	2029 ms	416 KiB

permutation

#include <bits/stdc++.h>
#include "permutation.h"
using namespace std;
int n;
vector <int> fin(257), v, a(257), q(257);
bitset <257> used;
void get (int x)
{
    used[a[x]] = 1;
    if (x == n && abs(a[1] - a[x]) == q[n])
    {
        vector <int> ret;
        for(int i = 1;i <= n; i++)
        {
            fin[v[i - 1]] = a[i];
        }
        for(int i = 1; i <= n; i++)
        {
            ret.push_back(fin[i]);
        }
        /*for (int i = 0; i < ret.size(); i++)
            cout << ret[i] << ' ';
        cout << "\n";*/
        answer(ret);
        exit(0);
    }
    else
    {
        int one = a[x] - q[x], two = a[x] + q[x];
        if (one > 0 && one <= n && !used[one] && abs(one - a[x]) == q[x])
        {
            a[x + 1] = one;
            get(x + 1);
        }
        if (two > 0 && two <= n && !used[two] && abs(two - a[x]) == q[x])
        {
            a[x + 1] = two;
            get(x + 1);
        }
    }
    used[a[x]] = 0;
    a[x] = 0;
}
void solve(int nn)
{
    n = nn;
    srand(chrono::steady_clock::now().time_since_epoch().count());
    for (int i = 1; i <= n; i++)
        v.push_back(i);
    random_shuffle(v.begin(), v.end());
    for(int i = 1; i <= n; i++)
    {
        rotate(v.begin(), v.begin() + 1, v.end());
        q[i] = query(v);
    }
    rotate(v.begin(), v.begin() + 1, v.end());
    int sum = 0;
    for(int i = 1; i <= n; i++)
        sum += q[i];
    sum /= (n - 1);
    for(int i = 1; i <= n; i++)
        q[i] = (sum - q[i]);
    q[n + 1] = q[1];
    for(int i = 1; i <= n; i++)
        q[i] = q[i + 1];
    /*for (int i = 0; i < v.size(); i++)
        cout << v[i] << ' ';
    cout << "\n";
    for (int i = 0; i < n + 2; i++)
        cout << q[i] << ' ';
    cout << "\n";*/
    //get(q, n);
    for (int i = 1; i <= n; i++)
    {
        for (int i2 = 1; i2 <= n; i2++)
            a[i2] = 0;
        a[1] = i;
        used.reset();
        get(1);
    }
    //answer(ans);
}

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: 15 / 15
• Subtask 2: 35 / 35
• Subtask 3: 50 / 50