Submission #583830

#	Time	Username	Problem	Language	Result	Execution time	Memory
583830		codebuster_10	Amusement Park (CEOI19_amusementpark)	C++17	100 / 100	2171 ms	5628 KiB

amusementpark

#include <bits/stdc++.h>
// #define int int64_t //be careful about this 

using namespace std;

#define vt vector 
#define ar array 
#define pr pair 

#define f first 
#define s second

#define pb push_back
#define eb emplace_back

#define fr(i,a,b) for(int i = (a); i < (b); ++i)
#define rf(i,a,b) for(int i = (b)-1; i >= (a); --i)
#define all(x) x.begin(),x.end()
#define mem(a,b) memset(a,b,sizeof(a))

namespace IN{
  template<class T> void re(vector<T> &A);
  template<class S,class T> void re(pair<S,T> &A);
  template<class T,size_t N> void re(array<T,N> &A);

  template<class T> void re(T& x){ 
    cin >> x;}
  template<class H, class... T> void re(H& h, T&... t){ 
    re(h); re(t...);}

  template<class T> void re(vector<T> &A){ 
    for(auto& x : A) re(x);}
  template<class S,class T> void re(pair<S,T> &A){ 
      re(A.first); re(A.second);}
  template<class T,size_t N> void re(array<T,N> &A){
    for(int i = 0; i < N; ++i)  re(A[i]);}
}

namespace OUT{
  template<class T>
  void __p(const T& a){ cout<<a; }
  template<class T, class F>
  void __p(const pair<T, F>& a){ cout<<"{"; __p(a.first); cout<<","; __p(a.second); cout<<"}\n"; }
  template<class T, size_t N>
  void __p(const array<T,N>& a){ cout<<"{"; for(int i=0;i<N;++i)__p(a[i]),cout<<",}\n"[i+1==N]; }
  template<class T>
  void __p(const vector<T>& a){
    cout<<"{";for(auto it=a.begin();it<a.end();it++)__p(*it),cout<<",}\n"[it+1==a.end()]; }
  template<class T, class ...Arg>
  void __p(T a1, Arg ...a){__p(a1); __p(a...); }
  template<class Arg1>
  void __f(const char *s, Arg1 &&arg1){ cout<<s<<" : "; __p(arg1); cout<<endl; }
  template<class Arg1, class ... Args>
  void __f(const char *ss, Arg1 &&arg1, Args &&... args){
    int b=0,i=0; do{ if(ss[i]=='(') b++; if(ss[i]==')') b--; i++;}while(!(ss[i]==','&&b==0));
    const char *comma=ss+i; cout.write(ss,comma-ss)<<" : ";__p(arg1);cout<<" | ";__f(comma+1,args...);}
  #define trace(...) cout<<"Line:"<<__LINE__<<"  ", __f(#__VA_ARGS__, __VA_ARGS__)
}


namespace FUNC{
  void IO(string s = ""){
    ios_base::sync_with_stdio(NULL); 
    cin.tie(nullptr); 
    cout.precision(20); 
    cout << fixed;
    if(!s.empty()){
      freopen((s+".in").c_str(),"r",stdin);
      freopen((s+".out").c_str(),"w",stdout);
    }
  }

  const auto start_time = chrono::high_resolution_clock::now();
  void output_run_time(){
    // will work for ac,cc&&cf.
#ifndef ONLINE_JUDGE
    auto end_time = chrono::high_resolution_clock::now();
    chrono::duration<double> diff = end_time-start_time;
      cout << "\n\n\nTime Taken : " << diff.count();
#endif
  }

  template<class T> bool ckmin(T& a, const T& b){ 
    return b < a ? a = b, true : false; }
    
  template<class T> bool ckmax(T& a, const T& b){ 
    return a < b ? a = b, true : false; }

  mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
  int my_rand(int L, int R){ 
    return uniform_int_distribution<int>(L,R)(rng); }
  
  template<class T> int sz(const T& x){ 
    return int(x.size()); }

  template<class T> int lb(const vector<T>& vec,const T& val){
    return int(lower_bound(vec.begin(), vec.end(),val) - vec.begin()); }

  template<class T> int ub(const vector<T>& vec,const T& val){
    return int(upper_bound(vec.begin(), vec.end(),val) - vec.begin()); }

  constexpr int  dx[4] = {1,0,-1,0};
  constexpr int  dy[4] = {0,1,0,-1};
  constexpr char dr[4] = {'D','R','U','L'};

  constexpr long long INFLL1 = 1e16, INFLL2 = 9e18;
  constexpr int INF = 2e9;

  template<class T>
  vector<T> V(int n,T val){
    return vector<T> (n,val);
  }

  template<class T>
  vector<vector<T>> V(int n,int m,T val){
    return vector<vector<T>> (n,vector<T> (m,val));
  }

  template<class T>
  vector<vector<vector<T>>> V(int n,int m,int k,T val){
    return vector<vector<vector<T>>> (n,vector<vector<T>> (m,vector<T> (k,val)));
  }
}


using namespace IN;
using namespace OUT;
using namespace FUNC;





















template<const unsigned &MOD>
struct _m_uint {
  unsigned val;
 
  _m_uint(int64_t v = 0){
    if(v < 0) v = v % MOD + MOD;
    if(v >= MOD) v %= MOD;
    val = unsigned(v);
  }
 
  _m_uint(uint64_t v){
    if(v >= MOD) v %= MOD;
    val = unsigned(v);
  }
 
  _m_uint(int v) : _m_uint(int64_t(v)) {}
  _m_uint(unsigned v) : _m_uint(uint64_t(v)) {}
 
  explicit operator unsigned() const { return val; }
  explicit operator int64_t() const { return val; }
  explicit operator uint64_t() const { return val; }
  explicit operator double() const { return val; }
  explicit operator long double() const { return val; }
 
  _m_uint& operator+=(const _m_uint &other){
    val = val < MOD - other.val ? val + other.val : val - (MOD - other.val);
    return *this;
  }
 
  _m_uint& operator-=(const _m_uint &other){
    val = val < other.val ? val + (MOD - other.val) : val - other.val;
    return *this;
  }
 
  static unsigned fast_mod(uint64_t x, unsigned m = MOD){
    return unsigned(x % m);
  }
 
  _m_uint& operator*=(const _m_uint &other){
    val = fast_mod(uint64_t(val) * other.val);
    return *this;
  }
 
  _m_uint& operator/=(const _m_uint &other){
    return *this *= other.inv();
  }
 
  friend _m_uint operator+(const _m_uint &a, const _m_uint &b){ return _m_uint(a) += b; }
  friend _m_uint operator-(const _m_uint &a, const _m_uint &b){ return _m_uint(a) -= b; }
  friend _m_uint operator*(const _m_uint &a, const _m_uint &b){ return _m_uint(a) *= b; }
  friend _m_uint operator/(const _m_uint &a, const _m_uint &b){ return _m_uint(a) /= b; }
 
  _m_uint& operator++(){
    val = val == MOD - 1 ? 0 : val + 1;
    return *this;
  }
 
  _m_uint& operator--(){
    val = val == 0 ? MOD - 1 : val - 1;
    return *this;
  }
    
  _m_uint operator++(int){ _m_uint before = *this; ++*this; return before; }
  _m_uint operator--(int){ _m_uint before = *this; --*this; return before; }
      
  _m_uint operator-() const {
    return val == 0 ? 0 : MOD - val;
  }
 
  friend bool operator==(const _m_uint &a, const _m_uint &b) { return a.val == b.val; }
  friend bool operator!=(const _m_uint &a, const _m_uint &b) { return a.val != b.val; }
  friend bool operator<(const _m_uint &a, const _m_uint &b) { return a.val < b.val; }
  friend bool operator>(const _m_uint &a, const _m_uint &b) { return a.val > b.val; }
  friend bool operator<=(const _m_uint &a, const _m_uint &b) { return a.val <= b.val; }
  friend bool operator>=(const _m_uint &a, const _m_uint &b) { return a.val >= b.val; }
 
  static const int SAVE_INV = int(1e6) + 5;
  static _m_uint save_inv[SAVE_INV];
 
  static void prepare_inv(){
    // Make sure MOD is prime, which is necessary for the inverse algorithm below.
    for(int64_t p = 2; p * p <= MOD; p += p % 2 + 1){
      assert(MOD % p != 0);
    } 
      
    save_inv[0] = 0;
    save_inv[1] = 1;
 
    for (int i = 2; i < SAVE_INV; i++){
      save_inv[i] = save_inv[MOD % i] * (MOD - MOD / i);
    }
  }
 
  _m_uint inv() const {
    if(save_inv[1] == 0)  
      prepare_inv();
 
    if(val < SAVE_INV)  
      return save_inv[val];
 
    _m_uint product = 1;
    unsigned v = val;
 
    while(v >= SAVE_INV){
      product *= MOD - MOD / v;
      v = MOD % v;
    }
    return product * save_inv[v];
  }
 
  _m_uint pow(int64_t p) const {
    if(p < 0)  
      return inv().pow(-p);
    _m_uint a = *this, result = 1;
    while(p > 0){
      if(p & 1) 
        result *= a;
      p >>= 1;
      if(p > 0) 
        a *= a;
    }
    return result;
  }
 
  friend ostream& operator<<(ostream &os, const _m_uint &m){
    return os << m.val;
  }
};
 
template<const unsigned &MOD> _m_uint<MOD> _m_uint<MOD>::save_inv[_m_uint<MOD>::SAVE_INV];

const unsigned MOD = 998244353;
using mint = _m_uint<MOD>;

constexpr int N = 18;

bool e[N][N], is[1<<N];
mint dp[1<<N];

signed main(){
  IO();
    
  int n,m;
  re(n,m);

  fr(_,0,m){
    int u,v; re(u,v); --u,--v;
    e[u][v] = e[v][u] = true;
  }

  is[0] = true;
  fr(mask,1,1<<n){
    if(is[mask & (mask - 1)]){
      is[mask] = true;
      int lsb = __builtin_ctz(mask);
      fr(i,0,n){
        if((mask>>i&1) && e[lsb][i]){
          is[mask] = false; 
        }
      }
    }
  }

  dp[0] = 1;

  fr(mask,1,1<<n){
    for(int submask = mask; submask > 0; submask = (submask - 1) & mask){
      if(is[submask]){
        dp[mask] += (__builtin_popcount(submask)%2 == 1 ? 1 : -1) * dp[mask^submask];
      }
    }
  }

  cout << m * dp[(1<<n)-1] / mint(2);







  //output_run_time();
  return 0;
}

Compilation message (stderr)

amusementpark.cpp: In function 'void FUNC::IO(std::string)':
amusementpark.cpp:68:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |       freopen((s+".in").c_str(),"r",stdin);
      |       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
amusementpark.cpp:69:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |       freopen((s+".out").c_str(),"w",stdout);
      |       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 12 / 12
• Subtask 3: 23 / 23
• Subtask 4: 21 / 21
• Subtask 5: 37 / 37