#263827 (C++14) No.696 square1001 and Permutation 5

• 問題: No.696 square1001 and Permutation 5
• ユーザー: どらら
• 提出日時: 2018-06-09 00:07:43
• 言語: C++14 (gcc 13.3.0 + boost 1.87.0)
• 結果: MLE
• 実行時間: -
• コード長: 5,962 bytes
• コンパイル時間: 2,747 ms
• コンパイル使用メモリ: 200,588 KB
• 実行使用メモリ: 814,780 KB
• 最終ジャッジ日時: 2024-06-30 11:29:05
• 合計ジャッジ時間: 6,948 ms
• ジャッジサーバーID （参考情報）: judge2 / judge3

ファイルパターン	結果
sample	-- * 2
other	MLE * 1 -- * 11

ソースコード

#include <bits/stdc++.h>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;
typedef unsigned long long ull;

class BIT{
  static const int MAX_N = 1 << 21;
  int n;
  vector<int> bit;
public:
  BIT(int n_):bit(MAX_N+1){
    n = n_;
    for(int i=0; i<n+1; i++) bit[i] = 0;
  }
  int sum(int i){
    int s = 0;
    while(i>0){
      s+=bit[i];
      i-=i&(-i);
    }
    return s;
  }
  void add(int i, int x){
    while(i<=n){
      bit[i]+=x;
      i+=i&(-i);
    }
  }
};


const long double PI = 4.0 * atan(1);
typedef std::vector< std::complex<long double> > VComp;

void fft(VComp& a, long double theta){
  int n = a.size();
  for(int m=n; m>=2; m>>=1){
    for(int i=0; i<(m>>1); i++){
      std::complex<long double> w = exp(i*theta*std::complex<long double>(0,1));
      for(int j=i; j<n; j+=m){
        int k=j+(m>>1);
        std::complex<long double> x = a[j]-a[k];
        a[j] += a[k];
        a[k] = w*x;
      }
    }
    theta *= 2;
  }

  int i=0;
  for(int j=1; j<n-1; j++){
    for(int k=n>>1; k>(i^=k); k>>=1);
    if(j<i) swap(a[i], a[j]);
  }
  
  if(theta<0){
    for(int i=0; i<a.size(); i++){
      a[i] /= n;
    }
  }
}

VComp str2vec(const std::string& str, int n){
  VComp ret(n, std::complex<long double>(0,0));
  for(int i=str.length()-1,j=0; i>=0; i--,j++){
    ret[j] = str[i] - '0';
  }
  return ret;
}

VComp VComp_mult(const VComp& a, const VComp& b){
  VComp ret(a.size(), std::complex<long double>(0,0));
  for(int i=0; i<a.size(); i++){
    ret[i] = a[i] * b[i];
  }
  return ret;
}


void print(const VComp& v){
  for(int i=0; i<v.size(); i++){
    std::cout << i << " : " << real(v[i]) << " " << imag(v[i]) << std::endl;
  }
}

std::string fft_multi(const std::string& str1, const std::string& str2){
  int n = 1;
  while(str1.size()+str2.size() >= n) n <<= 1;

  VComp ret1 = str2vec(str1, n);
  VComp ret2 = str2vec(str2, n);
  fft(ret1, 2 * PI / n);
  fft(ret2, 2 * PI / n);
  VComp ret = VComp_mult(ret1, ret2);

  fft(ret, -2 * PI / n);
  //print(ret);

  std::string ans = "";
  int carry = 0;
  int nonzero_idx = 0;
  for(int i=0; i<ret.size(); i++){
    if(real(ret[i])<0) ret[i] *= 0;
    if(i == 0){
      ans += (char)('0' + (int)(real(ret[i])+0.5)%10);
    }else{
      int tmp = carry + (int)(real(ret[i-1])+0.5)/10 + (int)(real(ret[i])+0.5)%10;
      carry = carry/10 + tmp/10;
      tmp %= 10;
      ans += (char)('0' + tmp);
      if(tmp != 0) nonzero_idx = i;
    }
  }
  if(carry > 0){
    ans += (char)('0' + carry);
    nonzero_idx = ret.size();
  }

  std::string noleadingzero = ans.substr(0,nonzero_idx+1);
  std::reverse(noleadingzero.begin(), noleadingzero.end());

  return noleadingzero;
}


class Bignum{
public:
  Bignum(){}
  Bignum(string s){
    for(int i=0;i<s.length();i++) d.push_front(s[i]-'0');
    normalize();
  }
  Bignum &normalize(){
    for(int i=d.size()-1;i>=0;i--){ if(d[i]!=0) break; d.pop_back(); }
    return *this;
  }
  int operator[](int i){ return i>=d.size()?0:d[i]; }
  int size(){ return normalize(),d.size(); }
  void toZero(){ d.clear(); d.push_front(0); }
  void toOne(){ d.clear(); d.push_front(1); }
  Bignum &inc(){ Bignum one("1"); return operator+=(one); }
  Bignum &operator+=(Bignum n){
    int l=max(size(),n.size());
    d.resize(l+1,0);
    for(int c=0,i=0;i<=l;i++) d[i]=(c=d[i]+n[i]+c/10)%10;
    return normalize();
  }
  Bignum &operator-=(Bignum n){
    //assert(size()>=n.size());
    for(int c=0,i=0;i<d.size();i++) d[i]=((c=d[i]-n[i]+(c-9)/10)+10)%10;
    return normalize();
  }
  Bignum &operator*=(int n){
    for(int i=0;i<15;i++) d.push_back(0);
    for(int c=0,i=0;i<d.size();i++) d[i]=(c=d[i]*n+c/10)%10;
    return normalize();
  }
  Bignum &operator*=(ull n){
    for(int i=0;i<25;i++) d.push_back(0);
    for(ull c=0,i=0;i<d.size();i++) d[i]=(c=d[i]*n+c/10ULL)%10ULL;
    return normalize();
  }
  Bignum operator+(Bignum n){ return Bignum(*this)+=n; }
  Bignum operator-(Bignum n){ return Bignum(*this)-=n; }
  Bignum operator*(int n){ return Bignum(*this)*=n; }
  Bignum operator*(ull n){ return Bignum(*this)*=n; }
  Bignum operator*(Bignum n){
    Bignum ret;
    int ka=size(),kb=n.size();
    ret.d.resize(ka+kb,0);
    for(int i=0;i<ka;i++) for(int c=0,j=0;j<=kb;j++) ret.d[i+j]=(c=ret.d[i+j]+d[i]*n[j]+c/10)%10;
    return ret.normalize();
  }
  Bignum &operator*=(Bignum n){ return (*this)=(*this)*n; }

  int div(int n){
    int c=0;
    for(int i=size()-1;i>=0;i--) d[i]=(c=c%n*10+d[i])/n;
    return c%n;
  }
  Bignum &operator<<=(int n){
    for(int i=0;i<n;i++) d.push_front(0);
    return normalize();
  }
  Bignum operator<<(int n){ return Bignum(*this)<<=n; }
  bool operator>(Bignum n){
    if(size()!=n.size()) return size()>n.size();
    for(int i=size()-1;i>=0;i--) if(d[i]!=n[i]) return d[i]>n[i];
    return false;
  }
  deque<int> d;
};
ostream &operator<<(ostream &os, const Bignum &l)
{
  Bignum n=l;
  if (n.size()==0) os<<0;
  else for (int i=n.d.size()-1;i>=0;i--) os<<n.d[i];
  return os;
}


int main(){
  int N;
  cin >> N;
  vector<int> v;
  rep(i,N){
    int p;
    cin >> p;
    v.push_back(p);
  }
  
  BIT bit(1<<20);
  vector<Bignum> v_num(N);
  vector<Bignum> v_p(N);
  Bignum p("1");
  for(int i=N-1; i>=0; i--){
    ull num = bit.sum(v[i]);
    v_num[i].toOne();
    v_num[i] *= num;
    v_p[i] = p;
    p *= N-i;
    bit.add(v[i], 1);
  }

  Bignum ret("1");
  rep(j,N){
    string tmp1="", tmp2="";
    {
      if(v_num[j].d.size() == 0) tmp1 = "0";
      else for (int i=v_num[j].d.size()-1;i>=0;i--) tmp1 += '0' + v_num[j].d[i];
    }
    {
      if(v_p[j].d.size() == 0) tmp2 = "0";
      else for (int i=v_p[j].d.size()-1;i>=0;i--) tmp2 += '0' + v_p[j].d[i];
    }

    string tmp_nump = fft_multi(tmp1, tmp2);
    Bignum b(tmp_nump);
    ret += b;
  }

  cout << ret << endl;
  
  return 0;
}