Submission #685384

#	Time	Username	Problem	Language	Result	Execution time	Memory
685384		dranaya_dusha	Secret Permutation (RMI19_permutation)	C++17	0 / 100	0 ms	296 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, int p, int n)
{
    ans.assign(n, 0);
    vector<int> used(n+1);
    ans[p]=1;
    used[1]=1;
    for (int i=p; i<n-1; i++)
        if (ans[i]+q[i]<=n && !used[ans[i]+q[i]]){
            ans[i+1]=ans[i]+q[i];
            used[ans[i]+q[i]]=1;
        }
        else if (ans[i]-q[i]>0 && !used[ans[i]-q[i]])
        {
            ans[i+1]=ans[i]-q[i];
            used[ans[i]-q[i]]=1;
        }
        else return false;
    for (int i=p; i>0; i--)
    {
        if (ans[i] + q[i - 1] <= n && !used[ans[i] + q[i - 1]]){
            ans[i - 1] = ans[i] + q[i - 1];
            used[ans[i] + q[i - 1]] = 1;
        }
        else if (ans[i] - q[i - 1] > 0 && !used[ans[i] - q[i - 1]])
        {
            ans[i-1] = ans[i]-q[i - 1];
            used[ans[i] - q[i - 1]] = 1;
        }
        else return false;
    }
    return true;
}


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

void solve(int n) {

    vector<int> V = {1, 2};
    vector<int> q(n-1);
    for (int i=0; i<n-1; i++){
        q[i] = query(V);
        V[0]++;
        V[1]++;
    }
    check2(q, n);
    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