Submission #685415

#	Time	Username	Problem	Language	Result	Execution time	Memory
685415		dranaya_dusha	Secret Permutation (RMI19_permutation)	C++17	0 / 100	0 ms	208 KiB

permutation

#pragma GCC optimize ("Ofast")
#include <bits/stdc++.h>
////#define int long long
//#define mp make_pair
//#define pb push_back
//#define fi first
//#define se second
//#define pii pair <int, int>


#include "permutation.h"
using namespace std;
vector<int> ans;

bool check (vector<int> &q, vector<int> &v, int p, int n)
{
    ans.assign(n, 0);
    vector<int> used(n+1);
    ans[v[p]-1]=1;
    used[1]=1;
    for (int i=p; i<n-1; i++)
        if (ans[v[i]-1]+q[i]<=n && !used[ans[v[i]-1]+q[i]]){
            ans[v[i+1]-1]=ans[v[i]-1]+q[i];
            used[ans[v[i]-1]+q[i]]=1;
        }
        else if (ans[v[i]-1]-q[i]>0 && !used[ans[v[i]-1]-q[i]])
        {
            ans[v[i+1]-1]=ans[v[i]-1]-q[i];
            used[ans[v[i]-1]-q[i]]=1;
        }
        else return false;
    for (int i=p; i>0; i--)
    {
        if (ans[v[i]-1]+q[i-1]<=n && !used[ans[v[i]-1]+q[i-1]]){
            ans[v[i-1]-1]=ans[v[i]-1]+q[i-1];
            used[ans[v[i]-1]+q[i-1]]=1;
        }
        else if (ans[v[i]-1]-q[i-1]>0 && !used[ans[v[i]-1]-q[i-1]])
        {
            ans[v[i-1]-1]=ans[v[i]-1]-q[i-1];
            used[ans[v[i]-1]-q[i-1]]=1;
        }
        else return false;
    }
    return true;
}

//
//void check2(vector<int>&q, vector<int> &v, int n)
//{
//    vector<int> v2;
//    for (int i=1; i<=n; i++)
//        v2.push_back(i);
//    vector<int> a(n);
//    for (int i=1; i<=n; i++)
//        a[i-1]=i;
//    random_shuffle(v2.begin(), v2.end());
//        int res=query(v2);
//    do
//    {
//
//        bool mark = 1;
//        for (int i=0; i<n-1; i++)
//            if (abs(a[i]-a[i+1])!=q[i]) mark = 0;
//        if (abs(a[n-1]-a[0])!=q[n-1]) mark=0;
//        if (mark){
//            ans = a;
//            return;
//        }
//    }while (next_permutation(a.begin(), a.end()));
//}

void solve(int n) {

    vector<int> v;
    for (int i=1; i<=n; i++)
        v.push_back(i);
    srand(time(NULL));
    random_shuffle(v.begin(), v.end());
    vector<int> q(n);
    for(int i=0;i<n;i++){
        rotate(v.begin(),v.begin()+1,v.end());
        q[i] = query(v);
    }
//    for (int i=0; i<n; i++)
//        cout << q[i] << ' ';
    rotate(v.begin(),v.begin()+1,v.end());
    int sum=0;
    for(int i=0;i<n;i++){
        sum+=q[i];
    }
    sum/=(n-1);
    for(int i=0;i<n;i++) q[i]=(sum-q[i]);
    rotate(q.begin(),q.begin()+1,q.end());
//    for (int i=0; i<n; i++)
//        cout << q[i] << ' ';
//    cout << endl;
//        for (int i=0; i<n; i++)
//        cout << v[i] << ' ';
//    cout << endl;

    ans.assign(n, 0);
//check2(q,v, n);
    for (int i=0; i<n; i++)
        if (check(q,v, i, n)) break;
//    for (int i=0; i<n; i++)
//        cout << ans[i] <<' ';
    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: 0 / 15
• Subtask 2: 0 / 35
• Subtask 3: 0 / 50