string/rollinghash.cpp

• View this file on GitHub
• Last update: 2020-10-27 19:04:41+09:00

Required by

• string/rectanglehash.cpp

Verified with

• test/aoj/1312.test.cpp
• test/aoj/2292.test.cpp
• test/aoj/2444.test.cpp
• test/aoj/ALDS1_14_B.test.cpp
• test/aoj/ALDS1_14_C.test.cpp
• test/yukicoder/0399.test.cpp

Code

#ifndef call_from_test
#include<bits/stdc++.h>
using namespace std;
#endif
//BEGIN CUT HERE
template<typename T,T MOD,T B>
struct RollingHash{
  using ll = long long;
  vector<T> hash,po;
  RollingHash(vector<T> vs){init(vs);}
  RollingHash(string &s){
    vector<T> vs;
    for(char c:s) vs.emplace_back(c);
    init(vs);
  }
  void init(vector<T> vs){
    int n=vs.size();
    hash.assign(n+1,0);
    po.assign(n+1,1);
    for(int i=0;i<n;i++){
      hash[i+1]=((ll)hash[i]*B+vs[i])%MOD;
      po[i+1]=(ll)po[i]*B%MOD;
    }
  }
  //S[l, r)
  T find(int l,int r){
    T res=(ll)hash[r]+MOD-(ll)hash[l]*po[r-l]%MOD;
    return res>=MOD?res-MOD:res;
  }
};
//END CUT HERE
#ifndef call_from_test
//INSERT ABOVE HERE
signed main(){
  return 0;
}
#endif

#line 1 "string/rollinghash.cpp"

#include<bits/stdc++.h>
using namespace std;
#endif
//BEGIN CUT HERE
template<typename T,T MOD,T B>
struct RollingHash{
  using ll = long long;
  vector<T> hash,po;
  RollingHash(vector<T> vs){init(vs);}
  RollingHash(string &s){
    vector<T> vs;
    for(char c:s) vs.emplace_back(c);
    init(vs);
  }
  void init(vector<T> vs){
    int n=vs.size();
    hash.assign(n+1,0);
    po.assign(n+1,1);
    for(int i=0;i<n;i++){
      hash[i+1]=((ll)hash[i]*B+vs[i])%MOD;
      po[i+1]=(ll)po[i]*B%MOD;
    }
  }
  //S[l, r)
  T find(int l,int r){
    T res=(ll)hash[r]+MOD-(ll)hash[l]*po[r-l]%MOD;
    return res>=MOD?res-MOD:res;
  }
};
//END CUT HERE
#ifndef call_from_test
//INSERT ABOVE HERE
signed main(){
  return 0;
}
#endif

Back to top page