Submission #941878

#	Time	Username	Problem	Language	Result	Execution time	Memory
941878		abcvuitunggio	Secret Permutation (RMI19_permutation)	C++17	10 / 100	3015 ms	344 KiB

permutation

//#define NAM
#ifndef NAM
#include "permutation.h"
#endif // NAM
#include <bits/stdc++.h>
using namespace std;
#ifdef NAM
int n,cnt_q=0;
vector <int> p,q;
int query(vector <int> v){
    auto v2=v;
    sort(v2.begin(),v2.end());
    int ch=1;
    for (int i=0;i<v2.size();i++)
        ch&=(v2[i]==i+1);
    if (v2.size()!=n||!ch){
        cout << "Error: Not a permutation";
        exit(0);
    }
    cnt_q++;
    int res=0;
    for (int i=0;i<n-1;i++)
        res+=abs(p[v[i]-1]-p[v[i+1]-1]);
    return res;
}
void answer(vector <int> v){
    if (v!=p&&v!=q)
        cout << "Wrong Answer";
    else{
        cout << "Correct\n";
        cout << "You asked " << cnt_q << " queries";
    }
}
#endif // NAM
void solve(int n){
    vector <int> cur;
    for (int i=1;i<=n;i++)
        cur.push_back(i);
    int x=query(cur);
    while (x>n-1){
        for (int i=0;i<n;i++)
            for (int j=i+1;j<n;j++){
                reverse(cur.begin()+i,cur.begin()+j+1);
                int y=query(cur);
                if (y<x)
                    x=y;
                else
                    reverse(cur.begin()+i,cur.begin()+j+1);
            }
    }
    vector <int> ans(n,0);
    for (int i=1;i<=n;i++)
        ans[cur[i-1]-1]=i;
    answer(ans);
}
#ifdef NAM
int main(){
    cin >> n;
    for (int i=1;i<=n;i++)
        p.push_back(i);
    random_shuffle(p.begin(),p.end());
    for (int i:p)
        q.push_back(n-i+1);
    solve(n);
}
#endif // NAM

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: 3 / 15
• Subtask 2: 7 / 35
• Subtask 3: 0 / 50