Submission #1221103

#	Time	Username	Problem	Language	Result	Execution time	Memory
1221103		hmms127	Connecting Supertrees (IOI20_supertrees)	C++20	Compilation error	0 ms	0 KiB

supertrees

#include "supertrees.h"
#include <vector>
using namespace std;
struct DSU{
  vector<int>par,sz;
  void init(int n){
      par.resize(n+1);sz.resize(n+1);
      f2(0,n,1)par[i]=i,sz[i]=1;
  }  
  int root(int u){
      return par[u]==u ? u:par[u]=root(par[u]);
  }
  bool merge(int u,int v){
      int ru=root(u),rv=root(v);
      if(ru==rv)return 0;
      if(sz[ru]>sz[rv])swap(sz[ru],sz[rv]);
      par[ru]=rv;sz[rv]+=sz[ru];
      return 1;
  }
};

int construct(std::vector<std::vector<int>> p) {
	int n=p[0].size();
    vector<vector<int>>v(n,vector<int>(n,0));
    DSU d;d.init(n);
    for(int i=0;i<n;i++){
        for(int j=i+1;j<n;j++){
        if(i==j)continue;
        if(p[i][j]){
            if(d.root(i)==d.root(j))return 0;
            d.merge(u,v);
            v[i][j]=1;
            v[j][i]=1;
        }
        }
    }
    for(int i=0;i<n;i++){
        for(int j=i+1;j<n;j++){
            if(p[i][j])continue;
            if(d.root(i)==d.root(j))return 0;
        }
    }
	build(v);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In member function 'void DSU::init(int)':
supertrees.cpp:8:7: error: 'f2' was not declared in this scope
    8 |       f2(0,n,1)par[i]=i,sz[i]=1;
      |       ^~
supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:31:21: error: 'u' was not declared in this scope
   31 |             d.merge(u,v);
      |                     ^