datastructure/weightedunionfind.cpp

• View this file on GitHub
• Last update: 2020-10-27 19:32:25+09:00

Verified with

• test/aoj/DSL_1_B.test.cpp
• test/yukicoder/3592.test.cpp

Code

#ifndef call_from_test
#include<bits/stdc++.h>
using namespace std;
#endif
//BEGIN CUT HERE
template <typename T>
struct WeightedUnionFind{
  vector<int> rs,ps;
  vector<T> ws;

  WeightedUnionFind(int n):rs(n,1),ps(n),ws(n,T(0)){
    iota(ps.begin(),ps.end(),0);
  }

  int find(int x){
    if(x==ps[x]) return x;
    int t=find(ps[x]);
    ws[x]+=ws[ps[x]];
    return ps[x]=t;
  }

  T weight(int x){
    find(x);
    return ws[x];
  }

  bool same(int x,int y){
    return find(x)==find(y);
  }

  void unite(int x,int y,T w){
    w+=weight(x);
    w-=weight(y);
    x=find(x);y=find(y);
    if(x==y) return;
    if(rs[x]<rs[y]) swap(x,y),w=-w;
    rs[x]+=rs[y];
    ps[y]=x;
    ws[y]=w;
  }

  T diff(int x,int y){
    return weight(y)-weight(x);
  }
};
//END CUT HERE
#ifndef call_from_test
signed main(){
  return 0;
}
#endif

#line 1 "datastructure/weightedunionfind.cpp"

#include<bits/stdc++.h>
using namespace std;
#endif
//BEGIN CUT HERE
template <typename T>
struct WeightedUnionFind{
  vector<int> rs,ps;
  vector<T> ws;

  WeightedUnionFind(int n):rs(n,1),ps(n),ws(n,T(0)){
    iota(ps.begin(),ps.end(),0);
  }

  int find(int x){
    if(x==ps[x]) return x;
    int t=find(ps[x]);
    ws[x]+=ws[ps[x]];
    return ps[x]=t;
  }

  T weight(int x){
    find(x);
    return ws[x];
  }

  bool same(int x,int y){
    return find(x)==find(y);
  }

  void unite(int x,int y,T w){
    w+=weight(x);
    w-=weight(y);
    x=find(x);y=find(y);
    if(x==y) return;
    if(rs[x]<rs[y]) swap(x,y),w=-w;
    rs[x]+=rs[y];
    ps[y]=x;
    ws[y]=w;
  }

  T diff(int x,int y){
    return weight(y)-weight(x);
  }
};
//END CUT HERE
#ifndef call_from_test
signed main(){
  return 0;
}
#endif

Back to top page