datastructure/unionfind.cpp

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• Last update: 2020-10-27 19:32:25+09:00

Required by

• datastructure/skewheap.cpp
• graph/kruskal.cpp
• graph/lowlink.cpp
• linearalgebra/tree_theorem.cpp

Verified with

• test/aoj/0314.test.cpp
• test/aoj/0403.test.cpp
• test/aoj/2995.test.cpp
• test/aoj/DSL_1_A.test.cpp
• test/aoj/GRL_2_A.test.cpp
• test/yosupo/manhattanmst.test.cpp
• test/yosupo/unionfind.test.cpp
• test/yukicoder/9158.test.cpp

Code

#ifndef call_from_test
#include <bits/stdc++.h>
using namespace std;
#endif
//BEGIN CUT HERE
struct UnionFind{
  int num;
  vector<int> rs,ps;
  UnionFind(int n):num(n),rs(n,1),ps(n,0){
    iota(ps.begin(),ps.end(),0);
  }
  int find(int x){
    return (x==ps[x]?x:ps[x]=find(ps[x]));
  }
  bool same(int x,int y){
    return find(x)==find(y);
  }
  void unite(int x,int y){
    x=find(x);y=find(y);
    if(x==y) return;
    if(rs[x]<rs[y]) swap(x,y);
    rs[x]+=rs[y];
    ps[y]=x;
    num--;
  }
  int size(int x){
    return rs[find(x)];
  }
  int count() const{
    return num;
  }
};
//END CUT HERE
#ifndef call_from_test
//INSERT ABOVE HERE
signed main(){
  return 0;
}
#endif

#line 1 "datastructure/unionfind.cpp"

#include <bits/stdc++.h>
using namespace std;
#endif
//BEGIN CUT HERE
struct UnionFind{
  int num;
  vector<int> rs,ps;
  UnionFind(int n):num(n),rs(n,1),ps(n,0){
    iota(ps.begin(),ps.end(),0);
  }
  int find(int x){
    return (x==ps[x]?x:ps[x]=find(ps[x]));
  }
  bool same(int x,int y){
    return find(x)==find(y);
  }
  void unite(int x,int y){
    x=find(x);y=find(y);
    if(x==y) return;
    if(rs[x]<rs[y]) swap(x,y);
    rs[x]+=rs[y];
    ps[y]=x;
    num--;
  }
  int size(int x){
    return rs[find(x)];
  }
  int count() const{
    return num;
  }
};
//END CUT HERE
#ifndef call_from_test
//INSERT ABOVE HERE
signed main(){
  return 0;
}
#endif

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