제출 #1054162

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1054162		huutuan	Secret Permutation (RMI19_permutation)	C++14	77.14 / 100	7 ms	344 KiB

permutation

#include "permutation.h"

#include <bits/stdc++.h>

using namespace std;

mt19937 rng(69420);

int rand(int l, int r){
   return uniform_int_distribution<int>(l, r)(rng);
}

void solve(int n) {
   vector<int> ans(n+1);
   vector<int> v(n);
   iota(v.begin(), v.end(), 1);
   vector<int> d1(n+1);
   for (int i=0; i<n; ++i){
      d1[v[0]]=query(v);
      rotate(v.begin(), v.begin()+1, v.end());
   }
   int sum=accumulate(d1.begin(), d1.end(), 0)/(n-1);
   for (int &i:d1) i=sum-i;
   auto find=[&](int x, int y){
      if (x>y) swap(x, y);
      if (y-x==1) return d1[y];
      if (y-x==n-1) return d1[1];
      vector<int> vv(n);
      iota(vv.begin(), vv.end(), 1);
      rotate(vv.begin(), vv.begin()+x-1, vv.end());
      reverse(vv.begin(), vv.begin()+y-x);
      int s=query(vv);
      for (int i=1; i<n; ++i){
         if (abs(vv[i]-vv[i-1])==1){
            s-=d1[max(vv[i], vv[i-1])];
         }else if (abs(vv[i]-vv[i-1])==n-1){
            s-=d1[1];
         }
      }
      return s;
   };
   ans[2]=ans[1]+d1[2];
   for (int i=3; i+1<=n; i+=2){
      int t=find(i-2, i+1);
      int msk=0;
      if (abs(ans[i-1]-ans[i-2]+d1[i]+d1[i+1])==t){
         msk|=1;
         ans[i]=ans[i-1]+d1[i];
         ans[i+1]=ans[i]+d1[i+1];
      }
      if (abs(ans[i-1]-ans[i-2]+d1[i]-d1[i+1])==t){
         msk|=2;
         ans[i]=ans[i-1]+d1[i];
         ans[i+1]=ans[i]-d1[i+1];
      }
      if (abs(ans[i-1]-ans[i-2]-d1[i]+d1[i+1])==t){
         msk|=4;
         ans[i]=ans[i-1]-d1[i];
         ans[i+1]=ans[i]+d1[i+1];
      }
      if (abs(ans[i-1]-ans[i-2]-d1[i]-d1[i+1])==t){
         msk|=8;
         ans[i]=ans[i-1]-d1[i];
         ans[i+1]=ans[i]-d1[i+1];
      }
      if (__builtin_popcount(msk)!=1){
         int tt=find(i-2, i);
         if (tt==abs(ans[i-1]-ans[i-2]+d1[i])) ans[i]=ans[i-1]+d1[i];
         else ans[i]=ans[i-1]-d1[i];
         if (t==abs(ans[i]-ans[i-2]+d1[i+1])) ans[i+1]=ans[i]+d1[i+1];
         else ans[i+1]=ans[i]-d1[i+1];
      }
   }
   if (n&1){
      int t=find(n-2, n);
      if (abs(ans[n-1]-ans[n-2]+d1[n])==t){
         ans[n]=ans[n-1]+d1[n];
      }else{
         ans[n]=ans[n-1]-d1[n];
      }
   }
   ans.erase(ans.begin());
   int mn=*min_element(ans.begin(), ans.end());
   for (int &i:ans) i-=mn-1;
   answer(ans);
}

컴파일 시 표준 에러 (stderr) 메시지

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: 11.571435000000001 / 15
• Subtask 2: 27.000015 / 35
• Subtask 3: 38.57145 / 50