結果

問題 No.599 回文かい
ユーザー Haar
提出日時 2019-08-15 04:51:46
言語 C++17(1z)
(gcc 8.3.0)
結果
AC  
実行時間 86 ms
コード長 3,241 Byte
コンパイル時間 1,748 ms
使用メモリ 2,424 KB
最終ジャッジ日時 2019-11-12 23:09:56

テストケース

テストケース表示
入力 結果 実行時間
使用メモリ
0_0.txt AC 5 ms
2,088 KB
0_1.txt AC 4 ms
2,088 KB
0_2.txt AC 4 ms
2,092 KB
0_3.txt AC 5 ms
2,088 KB
1_0.txt AC 5 ms
2,088 KB
1_1.txt AC 4 ms
2,092 KB
1_2.txt AC 5 ms
2,092 KB
1_3.txt AC 4 ms
2,092 KB
1_4.txt AC 3 ms
2,092 KB
1_5.txt AC 5 ms
2,088 KB
2_0.txt AC 33 ms
2,380 KB
2_1.txt AC 21 ms
2,360 KB
2_2.txt AC 35 ms
2,356 KB
2_3.txt AC 23 ms
2,356 KB
2_4.txt AC 52 ms
2,420 KB
2_5.txt AC 58 ms
2,420 KB
2_6.txt AC 75 ms
2,420 KB
2_7.txt AC 86 ms
2,424 KB
3_0.txt AC 3 ms
2,092 KB
3_1.txt AC 5 ms
2,088 KB
3_2.txt AC 5 ms
2,092 KB
evil_0.txt AC 44 ms
2,412 KB
テストケース一括ダウンロード

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);}

const LLI mod = 1e9+7;

template <typename T, LLI BASE, LLI MOD> class RollingHash{
private:
  static vector<LLI> pow;

public:
  static void init(int N){
    pow.assign(N+1,0);
    pow[0] = 1;
    FORE(i,1,N){
      pow[i] = pow[i-1]*BASE % MOD;
    }
  }

  static vector<LLI> generate_hash(const T &s){
    vector<LLI> ret(s.size()+1);

    FORE(i,1,(int)s.size()){
      ret[i] = (ret[i-1]*BASE+s[i-1]) % MOD;
    }
    
    return ret;
  }

  static LLI hash(const vector<LLI> &shash, int i, int j){ // [i, j)
    return (shash[j] - shash[i] * pow[j-i] + MOD*MOD) % MOD;
  }

  static LLI hash(const T &p){
    LLI phash = 0;
    REP(i,(int)p.size()) phash = (phash*BASE+p[i]) % MOD;
    return phash;
  }
  /*
  static vector<int> find(const vector<LLI> &shash, const T &p){
    vector<int> ret;
    int pl = p.size();
    LLI phash = hash(p);
    REPE(i,sh-pl) if(hash(i,i+pl) == phash) ret.push_back(i);
    return ret;
    }*/
};

template <typename T, LLI BASE, LLI MOD> vector<LLI> RollingHash<T,BASE,MOD>::pow;



using RH = RollingHash<string,29,1000000007>;

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  RH::init(100000);

  string s;
  while(cin >> s){

    int n = s.size();
    int m = (n+1)/2;

    vector<LLI> dp(m+1);

    auto hs = RH::generate_hash(s);

    if(n%2==1){
      REP(i,m){
        dp[i+1] = 1;

        REP(j,i){
          if(RH::hash(hs,m+j,m+i) == RH::hash(hs,m-1-i,m-1-j)){
            (dp[i+1] += dp[j+1]) %= mod;
          }
        }
      }
    }else{

      dp[0] = 1;
      
      REP(i,m){
        dp[i+1] = 1;

        REPE(j,i){
          if(RH::hash(hs,m+j,m+1+i) == RH::hash(hs,m-1-i,m-j)){
            (dp[i+1] += dp[j]) %= mod;
          }
        }
      }
      //join(cerr, ALL(dp));

    }

    cout << dp[m] << endl;
  }

  return 0;
}
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