結果

問題 No.2893 Minahoshi (Hard)
コンテスト
ユーザー amentorimaru
提出日時 2024-08-13 22:50:36
言語 C++23
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 65 ms / 2,000 ms
コード長 5,303 bytes
コンパイル時間 4,529 ms
コンパイル使用メモリ 245,968 KB
実行使用メモリ 11,992 KB
最終ジャッジ日時 2024-09-13 20:52:24
合計ジャッジ時間 8,542 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge1
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 1
other AC * 49
権限があれば一括ダウンロードができます

ソースコード

diff # 

#define ATCODER
#define _USE_MATH_DEFINES
#include <stdio.h>
#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>
#include <string>
#include <cassert>
#include <numeric>
#include <unordered_map>
#include <unordered_set>
#include <queue>
#include <math.h>
#include <climits>
#include <set>
#include <map>
#include <list>
#include <random>
#include <iterator>
#include <bitset>
#include <chrono>
#include <type_traits>
using namespace std;

using ll = long long;
using ld = long double;
using pll = pair<ll, ll>;
using pdd = pair<ld, ld>;


#define FOR(i, a, b) for (ll i = (a); i < (b); i++)
#define REP(i, n) for (ll i = 0; i < (n); i++)
#define ROF(i, a, b) for (ll i = (b - 1); i >= (a); i--)
#define PER(i, n) for (ll i = n - 1; i >= 0; i--)
#define VL vector<ll>
#define VVL vector<vector<ll>>
#define VP vector<pair<ll, ll>>
#define LPQ(T) priority_queue<T, vector<T>, greater<T>>
#define all(i) begin(i), end(i)
#define SORT(i) sort(all(i))
#define EXISTBIT(x, i) (((x >> i) & 1) != 0)
#define CHMAX(n, v) n = n < v ? v : n
#define CHMIN(n, v) n = n > v ? v : n
#define MP(a, b) make_pair(a, b)
#define DET2(x1, y1, x2, y2) (x1) * (y2) - (x2) * (y1)
#define DET3(x1, y1, z1, x2, y2, z2, x3, y3, z3) (x1) * (y2) * (z3) + (x2) * (y3) * (z1) + (x3) * (y1) * (z2) - (z1) * (y2) * (x3) - (z2) * (y3) * (x1) - (z3) * (y1) * (x2)
#define INC(a)      \
  for (auto &v : a) \
    v++;
#define DEC(a)      \
  for (auto &v : a) \
    v--;
#define SQU(x) (x) * (x)

#ifdef ATCODER
#include <atcoder/all>
using namespace atcoder;
using mint = modint1000000007;
using mint2 = modint998244353;
#endif
template <typename T = ll>
vector<T> read(size_t n)
{
  vector<T> ts(n);
  for (size_t i = 0; i < n; i++)
    cin >> ts[i];
  return ts;
}

template <typename TV, const ll N>
void read_tuple_impl(TV &) {}
template <typename TV, const ll N, typename Head, typename... Tail>
void read_tuple_impl(TV &ts)
{
  get<N>(ts).emplace_back(*(istream_iterator<Head>(cin)));
  read_tuple_impl<TV, N + 1, Tail...>(ts);
}
template <typename... Ts>
decltype(auto) read_tuple(size_t n)
{
  tuple<vector<Ts>...> ts;
  for (size_t i = 0; i < n; i++)
    read_tuple_impl<decltype(ts), 0, Ts...>(ts);
  return ts;
}

using val = ll;
using func = ll;

val op(val a, val b)
{
  return max(a, b);
}
val e() { return -1e18; }

val mp(func f, val a)
{
  return a + f;
}
func comp(func f, func g)
{
  return f + g;
}
func id() { return 0; }

ll di[4] = {1, 0, -1, 0};
ll dj[4] = {0, 1, 0, -1};
ll si[4] = {0, 3, 3, 0};
ll sj[4] = {0, 0, 3, 3};
// ll di[4] = { -1,-1,1,1 };
// ll dj[4] = { -1,1,-1,1 };
ll di8[8] = {0, -1, -1, -1, 0, 1, 1, 1};
ll dj8[8] = {-1, -1, 0, 1, 1, 1, 0, -1};


void solve()
{
  ll n;
  cin>>n;
  vector<unordered_set<ll>> lfsr={
    {},
    {},
    {0,1},
    {0,1},
    {0,1},
    {0,2},
    {0,1},
    {0,1},
    {0,2,3,4},
    {0,4},
    {0,3},
    {0,2},
    {0,1,2,8},
    {0,1,2,5},
    {0,1,2,12},
    {0,1},
    {0,2,3,5},
    {0,3},
    {0,7},
    {0,1,2,5}
  };
  ll c=1;
  while((1<<c)+c-1 <= n){
    c++;
  }
  c--;
  if(lfsr[c].empty()){
    ll bn=1<<n;
    ll mnlcp=1e18;
    string ans;
    REP(b,bn){
      string tmp;
      REP(i,n){
        if(EXISTBIT(b,i)){
          tmp.push_back('b');
        }else{
          tmp.push_back('a');
        }
      }
      auto sa=suffix_array(tmp);
      auto lcp=lcp_array(tmp,sa);
      ll sum=0;
      REP(i,n-1)
        sum+=lcp[i];
      if(mnlcp>sum){
        mnlcp=sum;
        ans=tmp;
      }
    }
    cout<<ans<<endl;
  }else{
    ll bc=1<<c;
    VVL g(bc);
    ll first = 1<<(c-1);
    ll len=c;
    ll reg = first;
    while(1){
      ll bit=0;
      for(auto&v:lfsr[c]){
        bit^=(reg>>v) & 1;
      }
      ll n_reg = (reg>>1)|(bit<<(c-1));
      if(n_reg==first)
        break;
      assert(g[reg].empty());
      g[reg].push_back(n_reg);
      reg = n_reg;
      len++;
    }
    g[1].push_back(0);
    g[0].push_back(first);
    g[0].push_back(0);
    len+=3;

    auto output=[&](ll start){
      string ans;
      REP(b,c){
        if(EXISTBIT(start,b)){
          ans.push_back('b');
        }else{
          ans.push_back('a');
        }
      }
      ll now=start;
      while(1){
        assert(ans.size()<=n);
        if(ans.size()==n){
          // auto sa=suffix_array(ans);
          // auto lcp=lcp_array(ans,sa);
          // ll sum=0;
          // REP(i,n-1)
          //   sum+=lcp[i];
          // cout<<sum<<":"<<ans<<endl;
          cout<<ans<<endl;
          return;
        }
        if(g[now].back() >> (c-1)){
          ans.push_back('b');
        }else{
          ans.push_back('a');
        }
        ll next=g[now].back();
        g[now].pop_back();
        now=next;
      }
    };
    if(len>=n){
      output(first);
      return;
    }
    REP(b,bc){
      if(g[b].size()>1)continue;
      first = b;
      reg = b;
      VL adds;
      while(1){
        ll n_reg = g[reg][0] ^ (1<<(c-1));
        if(n_reg==first)
          break;
        adds.push_back(reg);
        g[reg].push_back(n_reg);
        reg = n_reg;
        len++;
      }
      if(len>=n){
        for(auto&v:adds){
          swap(g[v][0],g[v][1]);
        }
        output(first);
        return;
      }
    }
  }
  return;
}

int main()
{
  ll t = 1;
  cin >> t;
  while (t--)
  {
    solve();
  }
  return 0;
}
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