結果

問題 No.659 徘徊迷路
コンテスト
ユーザー Haar
提出日時 2019-09-01 05:44:14
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 68 ms / 2,000 ms
コード長 5,538 bytes
コンパイル時間 2,196 ms
コンパイル使用メモリ 208,368 KB
最終ジャッジ日時 2025-01-07 16:15:40
ジャッジサーバーID
（参考情報） 		judge2 / judge2
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 * 5
other AC * 12
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 # 

#include <bits/stdc++.h>
#define LLI long long int
#define FOR(v, a, b) for(LLI v = (a); v < (b); ++v)
#define FORE(v, a, b) for(LLI v = (a); v <= (b); ++v)
#define REP(v, n) FOR(v, 0, n)
#define REPE(v, n) FORE(v, 0, n)
#define REV(v, a, b) for(LLI v = (a); v >= (b); --v)
#define ALL(x) (x).begin(), (x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define ITR(it, c) for(auto it = (c).begin(); it != (c).end(); ++it)
#define RITR(it, c) for(auto it = (c).rbegin(); it != (c).rend(); ++it)
#define EXIST(c,x) ((c).find(x) != (c).end())
#define fst first
#define snd second
#define popcount __builtin_popcount
#define UNIQ(v) (v).erase(unique(ALL(v)), (v).end())
#define bit(i) (1LL<<(i))

#ifdef DEBUG
#include <misc/C++/Debug.cpp>
#else
#define dump(...) ((void)0)
#endif

#define gcd __gcd

using namespace std;
template <class T> constexpr T lcm(T m, T n){return m/gcd(m,n)*n;}

template <typename I> void join(ostream &ost, I s, I t, string d=" "){for(auto i=s; i!=t; ++i){if(i!=s)ost<<d; ost<<*i;}ost<<endl;}
template <typename T> istream& operator>>(istream &is, vector<T> &v){for(auto &a : v) is >> a; return is;}

template <typename T, typename U> bool chmin(T &a, const U &b){return (a>b ? a=b, true : false);}
template <typename T, typename U> bool chmax(T &a, const U &b){return (a<b ? a=b, true : false);}
template <typename T, size_t N, typename U> void fill_array(T (&a)[N], const U &v){fill((U*)a, (U*)(a+N), v);}

struct Init{
  Init(){
    cin.tie(0);
    ios::sync_with_stdio(false);
  }
}init;

template <typename T> struct SquareMatrix{
  int N;
  vector<vector<T>> matrix;
  
  SquareMatrix(int N): N(N), matrix(N, vector<T>(N)){}
  SquareMatrix(int N, const T &val): N(N), matrix(N, vector<T>(N, val)){}
  SquareMatrix(const vector<vector<T>> &matrix): N(matrix.size()), matrix(matrix){}
  SquareMatrix(const SquareMatrix<T> &) = default;
  SquareMatrix(SquareMatrix<T> &&) = default;
  SquareMatrix(initializer_list<initializer_list<T>> list): N(list.size()), matrix(N, vector<T>(N)){
    int i = 0;
    ITR(it1,list){
      int j = 0;
      ITR(it2,*it1){
        matrix[i][j] = *it2;
        ++j;
      }
      ++i;
    }
  }

  SquareMatrix& operator+=(const SquareMatrix &val){
    REP(i,N) REP(j,N) matrix[i][j] = matrix[i][j] + val[i][j];
    return *this;
  }

  SquareMatrix& operator-=(const SquareMatrix &val){
    REP(i,N) REP(j,N) matrix[i][j] = matrix[i][j] - val[i][j];
    return *this;
  }

  SquareMatrix& operator*=(const SquareMatrix &val){
    vector<vector<T>> temp(N, vector<T>(N));
    REP(i,N) REP(j,N) REP(k,N) temp[i][j] = temp[i][j] + matrix[i][k] * val[k][j];
    swap(matrix, temp);
    return *this;
  }

  inline const vector<T>& operator[](size_t i) const {return matrix[i];}
  inline vector<T>& operator[](size_t i){return matrix[i];}
  inline int size() const {return N;}
  
  static SquareMatrix<T> make_unit(int N){
    SquareMatrix<T> ret(N);
    REP(i,N) ret[i][i] = 1;
    return ret;
  }

  SquareMatrix<T> transpose(){
    SquareMatrix<T> ret(N);
    REP(i,N) REP(j,N) ret[i][j] = matrix[j][i];
    return ret;
  }
 
  T determinant(){
    int s = 0;
    REP(i,N){
      if(matrix[i][i] == 0){
        FOR(j,i+1,N){
          if(matrix[j][i] != 0){
            matrix[i].swap(matrix[j]);
            (s += 1) %= 2;
            break; 
          }
          if(j == N-1) return 0;
        }
      }
    
      FOR(j,i+1,N){
        T t = matrix[j][i] / matrix[i][i];
        REP(k,N) matrix[j][k] -= matrix[i][k] * t;
      }
    }
  
    T ret = s ? -1 : 1;
    REP(i,N) ret *= matrix[i][i];
    return ret;
  }

  void show(int w = 10){
    REP(i,N){
      cerr << (i==0 ? "⎛" : (i==N-1 ? "⎝" : "⎜"));
      REP(j,N) cerr << setw(w) << matrix[i][j] << " ";
      cerr << (i==0 ? "⎞" : (i==N-1 ? "⎠" : "⎟"));
      cerr << endl;
    }
  }
};

template <typename T> SquareMatrix<T> operator+(const SquareMatrix<T> &a, const SquareMatrix<T> &b){auto ret = a; ret += b; return ret;}
template <typename T> SquareMatrix<T> operator-(const SquareMatrix<T> &a, const SquareMatrix<T> &b){auto ret = a; ret -= b; return ret;}
template <typename T> SquareMatrix<T> operator*(const SquareMatrix<T> &a, const SquareMatrix<T> &b){auto ret = a; ret *= b; return ret;}

template <typename T> SquareMatrix<T> power(SquareMatrix<T> a, uint64_t p){
  int N = a.size();

  if(p == 0) return SquareMatrix<T>::make_unit(N);
  if(p == 1) return a;
  
  SquareMatrix<T> temp = power(a, p/2);
  auto ret = temp * temp;

  if(p%2) ret *= a;
 
  return ret;
}


constexpr pair<int,int> dir4[4] = {{0,1}, {0,-1}, {1,0}, {-1,0}};


int main(){
  int R,C,T;
  int sy,sx,gy,gx;
  while(cin >> R >> C >> T >> sy >> sx >> gy >> gx){
    vector<string> b(R); cin >> b;
    vector<vector<int>> index(R, vector<int>(C));

    {
      int k = 0;
      REP(i,R) REP(j,C) index[i][j] = k++;
    }

    SquareMatrix<double> m(R*C);
    REP(i,R){
      REP(j,C){
        if(b[i][j] == '.'){
          int s = index[i][j];

          int p = 0;

          for(auto &[y,x] : dir4){
            if(b[i+y][j+x] == '.'){
              p += 1;
            }
          }

          if(p == 0){
            m[s][s] = 1;
          }else{
            for(auto &[y,x] : dir4){
              if(b[i+y][j+x] == '.'){
                int t = index[i+y][j+x];
                m[t][s] = 1.0 / p;
              }
            }
          }
        }
      }
    }

    auto p = power(m,T);

    double ans = p[index[gy][gx]][index[sy][sx]];


    cout << fixed << setprecision(12) << ans << endl;
  }

  return 0;
}
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